ac5a73b5d9
15804 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Christian Brauner
|
ac5a73b5d9 |
tmpfs: verify {g,u}id mount options correctly
[ Upstream commit 0200679fc7953177941e41c2a4241d0b6c2c5de8 ]
A while ago we received the following report:
"The other outstanding issue I noticed comes from the fact that
fsconfig syscalls may occur in a different userns than that which
called fsopen. That means that resolving the uid/gid via
current_user_ns() can save a kuid that isn't mapped in the associated
namespace when the filesystem is finally mounted. This means that it
is possible for an unprivileged user to create files owned by any
group in a tmpfs mount (since we can set the SUID bit on the tmpfs
directory), or a tmpfs that is owned by any user, including the root
group/user."
The contract for {g,u}id mount options and {g,u}id values in general set
from userspace has always been that they are translated according to the
caller's idmapping. In so far, tmpfs has been doing the correct thing.
But since tmpfs is mountable in unprivileged contexts it is also
necessary to verify that the resulting {k,g}uid is representable in the
namespace of the superblock to avoid such bugs as above.
The new mount api's cross-namespace delegation abilities are already
widely used. After having talked to a bunch of userspace this is the
most faithful solution with minimal regression risks. I know of one
users - systemd - that makes use of the new mount api in this way and
they don't set unresolable {g,u}ids. So the regression risk is minimal.
Link: https://lore.kernel.org/lkml/CALxfFW4BXhEwxR0Q5LSkg-8Vb4r2MONKCcUCVioehXQKr35eHg@mail.gmail.com
Fixes:
|
||
Oscar Salvador
|
b3ac2c1d72 |
mm,hwpoison: fix printing of page flags
commit 6696d2a6f38c0beedf03c381edfc392ecf7631b4 upstream. Format %pG expects a lower case 'p' in order to print the flags. Fix it. Link: https://lkml.kernel.org/r/20210108085202.4506-1-osalvador@suse.de Fixes: 8295d535e2aa ("mm,hwpoison: refactor get_any_page") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Miaohe Lin
|
32f71ef627 |
mm: memory-failure: fix unexpected return value in soft_offline_page()
[ Upstream commit e2c1ab070fdc81010ec44634838d24fce9ff9e53 ]
When page_handle_poison() fails to handle the hugepage or free page in
retry path, soft_offline_page() will return 0 while -EBUSY is expected in
this case.
Consequently the user will think soft_offline_page succeeds while it in
fact failed. So the user will not try again later in this case.
Link: https://lkml.kernel.org/r/20230627112808.1275241-1-linmiaohe@huawei.com
Fixes:
|
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Kefeng Wang
|
20c2db79f1 |
mm: memory-failure: kill soft_offline_free_page()
[ Upstream commit 7adb45887c8af88985c335b53d253654e9d2dd16 ] Open-code the page_handle_poison() into soft_offline_page() and kill unneeded soft_offline_free_page(). Link: https://lkml.kernel.org/r/20220819033402.156519-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Stable-dep-of: e2c1ab070fdc ("mm: memory-failure: fix unexpected return value in soft_offline_page()") Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Dan Williams
|
406166a3ac |
mm: fix page reference leak in soft_offline_page()
[ Upstream commit dad4e5b390866ca902653df0daa864ae4b8d4147 ]
The conversion to move pfn_to_online_page() internal to
soft_offline_page() missed that the get_user_pages() reference taken by
the madvise() path needs to be dropped when pfn_to_online_page() fails.
Note the direct sysfs-path to soft_offline_page() does not perform a
get_user_pages() lookup.
When soft_offline_page() is handed a pfn_valid() && !pfn_to_online_page()
pfn the kernel hangs at dax-device shutdown due to a leaked reference.
Link: https://lkml.kernel.org/r/161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes:
|
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|
Oscar Salvador
|
749630ce91 |
mm,hwpoison: refactor get_any_page
[ Upstream commit 8295d535e2aa198bdf65a4045d622df38955ffe2 ] Patch series "HWPoison: Refactor get page interface", v2. This patch (of 3): When we want to grab a refcount via get_any_page, we call __get_any_page that calls get_hwpoison_page to get the actual refcount. get_any_page() is only there because we have a sort of retry mechanism in case the page we met is unknown to us or if we raced with an allocation. Also __get_any_page() prints some messages about the page type in case the page was a free page or the page type was unknown, but if anything, we only need to print a message in case the pagetype was unknown, as that is reporting an error down the chain. Let us merge get_any_page() and __get_any_page(), and let the message be printed in soft_offline_page. While we are it, we can also remove the 'pfn' parameter as it is no longer used. Link: https://lkml.kernel.org/r/20201204102558.31607-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20201204102558.31607-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Acked-by: Vlastimil Babka <Vbabka@suse.cz> Cc: Qian Cai <qcai@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Stable-dep-of: e2c1ab070fdc ("mm: memory-failure: fix unexpected return value in soft_offline_page()") Signed-off-by: Sasha Levin <sashal@kernel.org> |
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Alexandre Ghiti
|
f3c5697aae |
mm: add a call to flush_cache_vmap() in vmap_pfn()
commit a50420c79731fc5cf27ad43719c1091e842a2606 upstream. flush_cache_vmap() must be called after new vmalloc mappings are installed in the page table in order to allow architectures to make sure the new mapping is visible. It could lead to a panic since on some architectures (like powerpc), the page table walker could see the wrong pte value and trigger a spurious page fault that can not be resolved (see commit |
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Roberto Sassu
|
5fada37511 |
shmem: use ramfs_kill_sb() for kill_sb method of ramfs-based tmpfs
commit 36ce9d76b0a93bae799e27e4f5ac35478c676592 upstream.
As the ramfs-based tmpfs uses ramfs_init_fs_context() for the
init_fs_context method, which allocates fc->s_fs_info, use ramfs_kill_sb()
to free it and avoid a memory leak.
Link: https://lkml.kernel.org/r/20230607161523.2876433-1-roberto.sassu@huaweicloud.com
Fixes:
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Roberto Sassu
|
051d642133 |
memfd: check for non-NULL file_seals in memfd_create() syscall
[ Upstream commit 935d44acf621aa0688fef8312dec3e5940f38f4e ]
Ensure that file_seals is non-NULL before using it in the memfd_create()
syscall. One situation in which memfd_file_seals_ptr() could return a
NULL pointer when CONFIG_SHMEM=n, oopsing the kernel.
Link: https://lkml.kernel.org/r/20230607132427.2867435-1-roberto.sassu@huaweicloud.com
Fixes:
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David Hildenbrand
|
c374552b54 |
mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block
commit 8dc4bb58a146655eb057247d7c9d19e73928715b upstream. virtio-mem soon wants to use offline_and_remove_memory() memory that exceeds a single Linux memory block (memory_block_size_bytes()). Let's remove that restriction. Let's remember the old state and try to restore that if anything goes wrong. While re-onlining can, in general, fail, it's highly unlikely to happen (usually only when a notifier fails to allocate memory, and these are rather rare). This will be used by virtio-mem to offline+remove memory ranges that are bigger than a single memory block - for example, with a device block size of 1 GiB (e.g., gigantic pages in the hypervisor) and a Linux memory block size of 128MB. While we could compress the state into 2 bit, using 8 bit is much easier. This handling is similar, but different to acpi_scan_try_to_offline(): a) We don't try to offline twice. I am not sure if this CONFIG_MEMCG optimization is still relevant - it should only apply to ZONE_NORMAL (where we have no guarantees). If relevant, we can always add it. b) acpi_scan_try_to_offline() simply onlines all memory in case something goes wrong. It doesn't restore previous online type. Let's do that, so we won't overwrite what e.g., user space configured. Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20201112133815.13332-28-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Greg Thelen
|
047f618d19 |
writeback, cgroup: remove extra percpu_ref_exit()
5.10 stable commit |
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Tetsuo Handa
|
a992c387b4 |
mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock
commit 1007843a91909a4995ee78a538f62d8665705b66 upstream.
syzbot is reporting circular locking dependency which involves
zonelist_update_seq seqlock [1], for this lock is checked by memory
allocation requests which do not need to be retried.
One deadlock scenario is kmalloc(GFP_ATOMIC) from an interrupt handler.
CPU0
----
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount odd
// e.g. timer interrupt handler runs at this moment
some_timer_func() {
kmalloc(GFP_ATOMIC) {
__alloc_pages_slowpath() {
read_seqbegin(&zonelist_update_seq) {
// spins forever because zonelist_update_seq.seqcount is odd
}
}
}
}
// e.g. timer interrupt handler finishes
write_sequnlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount even
}
This deadlock scenario can be easily eliminated by not calling
read_seqbegin(&zonelist_update_seq) from !__GFP_DIRECT_RECLAIM allocation
requests, for retry is applicable to only __GFP_DIRECT_RECLAIM allocation
requests. But Michal Hocko does not know whether we should go with this
approach.
Another deadlock scenario which syzbot is reporting is a race between
kmalloc(GFP_ATOMIC) from tty_insert_flip_string_and_push_buffer() with
port->lock held and printk() from __build_all_zonelists() with
zonelist_update_seq held.
CPU0 CPU1
---- ----
pty_write() {
tty_insert_flip_string_and_push_buffer() {
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq);
build_zonelists() {
printk() {
vprintk() {
vprintk_default() {
vprintk_emit() {
console_unlock() {
console_flush_all() {
console_emit_next_record() {
con->write() = serial8250_console_write() {
spin_lock_irqsave(&port->lock, flags);
tty_insert_flip_string() {
tty_insert_flip_string_fixed_flag() {
__tty_buffer_request_room() {
tty_buffer_alloc() {
kmalloc(GFP_ATOMIC | __GFP_NOWARN) {
__alloc_pages_slowpath() {
zonelist_iter_begin() {
read_seqbegin(&zonelist_update_seq); // spins forever because zonelist_update_seq.seqcount is odd
spin_lock_irqsave(&port->lock, flags); // spins forever because port->lock is held
}
}
}
}
}
}
}
}
spin_unlock_irqrestore(&port->lock, flags);
// message is printed to console
spin_unlock_irqrestore(&port->lock, flags);
}
}
}
}
}
}
}
}
}
write_sequnlock(&zonelist_update_seq);
}
}
}
This deadlock scenario can be eliminated by
preventing interrupt context from calling kmalloc(GFP_ATOMIC)
and
preventing printk() from calling console_flush_all()
while zonelist_update_seq.seqcount is odd.
Since Petr Mladek thinks that __build_all_zonelists() can become a
candidate for deferring printk() [2], let's address this problem by
disabling local interrupts in order to avoid kmalloc(GFP_ATOMIC)
and
disabling synchronous printk() in order to avoid console_flush_all()
.
As a side effect of minimizing duration of zonelist_update_seq.seqcount
being odd by disabling synchronous printk(), latency at
read_seqbegin(&zonelist_update_seq) for both !__GFP_DIRECT_RECLAIM and
__GFP_DIRECT_RECLAIM allocation requests will be reduced. Although, from
lockdep perspective, not calling read_seqbegin(&zonelist_update_seq) (i.e.
do not record unnecessary locking dependency) from interrupt context is
still preferable, even if we don't allow calling kmalloc(GFP_ATOMIC)
inside
write_seqlock(&zonelist_update_seq)/write_sequnlock(&zonelist_update_seq)
section...
Link: https://lkml.kernel.org/r/8796b95c-3da3-5885-fddd-6ef55f30e4d3@I-love.SAKURA.ne.jp
Fixes: 3d36424b3b58 ("mm/page_alloc: fix race condition between build_all_zonelists and page allocation")
Link: https://lkml.kernel.org/r/ZCrs+1cDqPWTDFNM@alley [2]
Reported-by: syzbot <syzbot+223c7461c58c58a4cb10@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=223c7461c58c58a4cb10 [1]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Patrick Daly <quic_pdaly@quicinc.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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Baokun Li
|
2b00b2a0e6 |
writeback, cgroup: fix null-ptr-deref write in bdi_split_work_to_wbs
[ Upstream commit 1ba1199ec5747f475538c0d25a32804e5ba1dfde ] KASAN report null-ptr-deref: ================================================================== BUG: KASAN: null-ptr-deref in bdi_split_work_to_wbs+0x5c5/0x7b0 Write of size 8 at addr 0000000000000000 by task sync/943 CPU: 5 PID: 943 Comm: sync Tainted: 6.3.0-rc5-next-20230406-dirty #461 Call Trace: <TASK> dump_stack_lvl+0x7f/0xc0 print_report+0x2ba/0x340 kasan_report+0xc4/0x120 kasan_check_range+0x1b7/0x2e0 __kasan_check_write+0x24/0x40 bdi_split_work_to_wbs+0x5c5/0x7b0 sync_inodes_sb+0x195/0x630 sync_inodes_one_sb+0x3a/0x50 iterate_supers+0x106/0x1b0 ksys_sync+0x98/0x160 [...] ================================================================== The race that causes the above issue is as follows: cpu1 cpu2 -------------------------|------------------------- inode_switch_wbs INIT_WORK(&isw->work, inode_switch_wbs_work_fn) queue_rcu_work(isw_wq, &isw->work) // queue_work async inode_switch_wbs_work_fn wb_put_many(old_wb, nr_switched) percpu_ref_put_many ref->data->release(ref) cgwb_release queue_work(cgwb_release_wq, &wb->release_work) // queue_work async &wb->release_work cgwb_release_workfn ksys_sync iterate_supers sync_inodes_one_sb sync_inodes_sb bdi_split_work_to_wbs kmalloc(sizeof(*work), GFP_ATOMIC) // alloc memory failed percpu_ref_exit ref->data = NULL kfree(data) wb_get(wb) percpu_ref_get(&wb->refcnt) percpu_ref_get_many(ref, 1) atomic_long_add(nr, &ref->data->count) atomic64_add(i, v) // trigger null-ptr-deref bdi_split_work_to_wbs() traverses &bdi->wb_list to split work into all wbs. If the allocation of new work fails, the on-stack fallback will be used and the reference count of the current wb is increased afterwards. If cgroup writeback membership switches occur before getting the reference count and the current wb is released as old_wd, then calling wb_get() or wb_put() will trigger the null pointer dereference above. This issue was introduced in v4.3-rc7 (see fix tag1). Both sync_inodes_sb() and __writeback_inodes_sb_nr() calls to bdi_split_work_to_wbs() can trigger this issue. For scenarios called via sync_inodes_sb(), originally commit |
||
Peter Xu
|
2523d9d7bb |
mm/khugepaged: check again on anon uffd-wp during isolation
commit dd47ac428c3f5f3bcabe845f36be870fe6c20784 upstream. Khugepaged collapse an anonymous thp in two rounds of scans. The 2nd round done in __collapse_huge_page_isolate() after hpage_collapse_scan_pmd(), during which all the locks will be released temporarily. It means the pgtable can change during this phase before 2nd round starts. It's logically possible some ptes got wr-protected during this phase, and we can errornously collapse a thp without noticing some ptes are wr-protected by userfault. |
||
Rongwei Wang
|
ea8c42b3b6 |
mm/swap: fix swap_info_struct race between swapoff and get_swap_pages()
commit 6fe7d6b992113719e96744d974212df3fcddc76c upstream.
The si->lock must be held when deleting the si from the available list.
Otherwise, another thread can re-add the si to the available list, which
can lead to memory corruption. The only place we have found where this
happens is in the swapoff path. This case can be described as below:
core 0 core 1
swapoff
del_from_avail_list(si) waiting
try lock si->lock acquire swap_avail_lock
and re-add si into
swap_avail_head
acquire si->lock but missing si already being added again, and continuing
to clear SWP_WRITEOK, etc.
It can be easily found that a massive warning messages can be triggered
inside get_swap_pages() by some special cases, for example, we call
madvise(MADV_PAGEOUT) on blocks of touched memory concurrently, meanwhile,
run much swapon-swapoff operations (e.g. stress-ng-swap).
However, in the worst case, panic can be caused by the above scene. In
swapoff(), the memory used by si could be kept in swap_info[] after
turning off a swap. This means memory corruption will not be caused
immediately until allocated and reset for a new swap in the swapon path.
A panic message caused: (with CONFIG_PLIST_DEBUG enabled)
------------[ cut here ]------------
top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a
prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d
next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a
WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70
Modules linked in: rfkill(E) crct10dif_ce(E)...
CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+
Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015
pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
pc : plist_check_prev_next_node+0x50/0x70
lr : plist_check_prev_next_node+0x50/0x70
sp : ffff0018009d3c30
x29: ffff0018009d3c40 x28: ffff800011b32a98
x27: 0000000000000000 x26: ffff001803908000
x25: ffff8000128ea088 x24: ffff800011b32a48
x23: 0000000000000028 x22: ffff001800875c00
x21: ffff800010f9e520 x20: ffff001800875c00
x19: ffff001800fdc6e0 x18: 0000000000000030
x17: 0000000000000000 x16: 0000000000000000
x15: 0736076307640766 x14: 0730073007380731
x13: 0736076307640766 x12: 0730073007380731
x11: 000000000004058d x10: 0000000085a85b76
x9 : ffff8000101436e4 x8 : ffff800011c8ce08
x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff0017df9ed338 x4 : 0000000000000001
x3 : ffff8017ce62a000 x2 : ffff0017df9ed340
x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
plist_check_prev_next_node+0x50/0x70
plist_check_head+0x80/0xf0
plist_add+0x28/0x140
add_to_avail_list+0x9c/0xf0
_enable_swap_info+0x78/0xb4
__do_sys_swapon+0x918/0xa10
__arm64_sys_swapon+0x20/0x30
el0_svc_common+0x8c/0x220
do_el0_svc+0x2c/0x90
el0_svc+0x1c/0x30
el0_sync_handler+0xa8/0xb0
el0_sync+0x148/0x180
irq event stamp: 2082270
Now, si->lock locked before calling 'del_from_avail_list()' to make sure
other thread see the si had been deleted and SWP_WRITEOK cleared together,
will not reinsert again.
This problem exists in versions after stable 5.10.y.
Link: https://lkml.kernel.org/r/20230404154716.23058-1-rongwei.wang@linux.alibaba.com
Fixes:
|
||
|
David Hildenbrand
|
b2747b690c |
mm/userfaultfd: propagate uffd-wp bit when PTE-mapping the huge zeropage
commit 42b2af2c9b7eede8ef21d0943f84d135e21a32a3 upstream.
Currently, we'd lose the userfaultfd-wp marker when PTE-mapping a huge
zeropage, resulting in the next write faults in the PMD range not
triggering uffd-wp events.
Various actions (partial MADV_DONTNEED, partial mremap, partial munmap,
partial mprotect) could trigger this. However, most importantly,
un-protecting a single sub-page from the userfaultfd-wp handler when
processing a uffd-wp event will PTE-map the shared huge zeropage and lose
the uffd-wp bit for the remainder of the PMD.
Let's properly propagate the uffd-wp bit to the PMDs.
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <inttypes.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <poll.h>
#include <pthread.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <linux/userfaultfd.h>
static size_t pagesize;
static int uffd;
static volatile bool uffd_triggered;
#define barrier() __asm__ __volatile__("": : :"memory")
static void uffd_wp_range(char *start, size_t size, bool wp)
{
struct uffdio_writeprotect uffd_writeprotect;
uffd_writeprotect.range.start = (unsigned long) start;
uffd_writeprotect.range.len = size;
if (wp) {
uffd_writeprotect.mode = UFFDIO_WRITEPROTECT_MODE_WP;
} else {
uffd_writeprotect.mode = 0;
}
if (ioctl(uffd, UFFDIO_WRITEPROTECT, &uffd_writeprotect)) {
fprintf(stderr, "UFFDIO_WRITEPROTECT failed: %d\n", errno);
exit(1);
}
}
static void *uffd_thread_fn(void *arg)
{
static struct uffd_msg msg;
ssize_t nread;
while (1) {
struct pollfd pollfd;
int nready;
pollfd.fd = uffd;
pollfd.events = POLLIN;
nready = poll(&pollfd, 1, -1);
if (nready == -1) {
fprintf(stderr, "poll() failed: %d\n", errno);
exit(1);
}
nread = read(uffd, &msg, sizeof(msg));
if (nread <= 0)
continue;
if (msg.event != UFFD_EVENT_PAGEFAULT ||
!(msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WP)) {
printf("FAIL: wrong uffd-wp event fired\n");
exit(1);
}
/* un-protect the single page. */
uffd_triggered = true;
uffd_wp_range((char *)(uintptr_t)msg.arg.pagefault.address,
pagesize, false);
}
return arg;
}
static int setup_uffd(char *map, size_t size)
{
struct uffdio_api uffdio_api;
struct uffdio_register uffdio_register;
pthread_t thread;
uffd = syscall(__NR_userfaultfd,
O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
if (uffd < 0) {
fprintf(stderr, "syscall() failed: %d\n", errno);
return -errno;
}
uffdio_api.api = UFFD_API;
uffdio_api.features = UFFD_FEATURE_PAGEFAULT_FLAG_WP;
if (ioctl(uffd, UFFDIO_API, &uffdio_api) < 0) {
fprintf(stderr, "UFFDIO_API failed: %d\n", errno);
return -errno;
}
if (!(uffdio_api.features & UFFD_FEATURE_PAGEFAULT_FLAG_WP)) {
fprintf(stderr, "UFFD_FEATURE_WRITEPROTECT missing\n");
return -ENOSYS;
}
uffdio_register.range.start = (unsigned long) map;
uffdio_register.range.len = size;
uffdio_register.mode = UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register) < 0) {
fprintf(stderr, "UFFDIO_REGISTER failed: %d\n", errno);
return -errno;
}
pthread_create(&thread, NULL, uffd_thread_fn, NULL);
return 0;
}
int main(void)
{
const size_t size = 4 * 1024 * 1024ull;
char *map, *cur;
pagesize = getpagesize();
map = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
if (map == MAP_FAILED) {
fprintf(stderr, "mmap() failed\n");
return -errno;
}
if (madvise(map, size, MADV_HUGEPAGE)) {
fprintf(stderr, "MADV_HUGEPAGE failed\n");
return -errno;
}
if (setup_uffd(map, size))
return 1;
/* Read the whole range, populating zeropages. */
madvise(map, size, MADV_POPULATE_READ);
/* Write-protect the whole range. */
uffd_wp_range(map, size, true);
/* Make sure uffd-wp triggers on each page. */
for (cur = map; cur < map + size; cur += pagesize) {
uffd_triggered = false;
barrier();
/* Trigger a write fault. */
*cur = 1;
barrier();
if (!uffd_triggered) {
printf("FAIL: uffd-wp did not trigger\n");
return 1;
}
}
printf("PASS: uffd-wp triggered\n");
return 0;
}
Link: https://lkml.kernel.org/r/20230302175423.589164-1-david@redhat.com
Fixes:
|
||
Yin Fengwei
|
ed77831e69 |
mm/thp: check and bail out if page in deferred queue already
commit 81e506bec9be1eceaf5a2c654e28ba5176ef48d8 upstream. Kernel build regression with LLVM was reported here: https://lore.kernel.org/all/Y1GCYXGtEVZbcv%2F5@dev-arch.thelio-3990X/ with commit f35b5d7d676e ("mm: align larger anonymous mappings on THP boundaries"). And the commit f35b5d7d676e was reverted. It turned out the regression is related with madvise(MADV_DONTNEED) was used by ld.lld. But with none PMD_SIZE aligned parameter len. trace-bpfcc captured: 531607 531732 ld.lld do_madvise.part.0 start: 0x7feca9000000, len: 0x7fb000, behavior: 0x4 531607 531793 ld.lld do_madvise.part.0 start: 0x7fec86a00000, len: 0x7fb000, behavior: 0x4 If the underneath physical page is THP, the madvise(MADV_DONTNEED) can trigger split_queue_lock contention raised significantly. perf showed following data: 14.85% 0.00% ld.lld [kernel.kallsyms] [k] entry_SYSCALL_64_after_hwframe 11.52% entry_SYSCALL_64_after_hwframe do_syscall_64 __x64_sys_madvise do_madvise.part.0 zap_page_range unmap_single_vma unmap_page_range page_remove_rmap deferred_split_huge_page __lock_text_start native_queued_spin_lock_slowpath If THP can't be removed from rmap as whole THP, partial THP will be removed from rmap by removing sub-pages from rmap. Even the THP head page is added to deferred queue already, the split_queue_lock will be acquired and check whether the THP head page is in the queue already. Thus, the contention of split_queue_lock is raised. Before acquire split_queue_lock, check and bail out early if the THP head page is in the queue already. The checking without holding split_queue_lock could race with deferred_split_scan, but it doesn't impact the correctness here. Test result of building kernel with ld.lld: commit 7b5a0b664ebe (parent commit of f35b5d7d676e): time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all 6:07.99 real, 26367.77 user, 5063.35 sys commit f35b5d7d676e: time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all 7:22.15 real, 26235.03 user, 12504.55 sys commit f35b5d7d676e with the fixing patch: time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all 6:08.49 real, 26520.15 user, 5047.91 sys Link: https://lkml.kernel.org/r/20221223135207.2275317-1-fengwei.yin@intel.com Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Johannes Weiner
|
e6d20325f4 |
mm: memcontrol: deprecate charge moving
commit da34a8484d162585e22ed8c1e4114aa2f60e3567 upstream. Charge moving mode in cgroup1 allows memory to follow tasks as they migrate between cgroups. This is, and always has been, a questionable thing to do - for several reasons. First, it's expensive. Pages need to be identified, locked and isolated from various MM operations, and reassigned, one by one. Second, it's unreliable. Once pages are charged to a cgroup, there isn't always a clear owner task anymore. Cache isn't moved at all, for example. Mapped memory is moved - but if trylocking or isolating a page fails, it's arbitrarily left behind. Frequent moving between domains may leave a task's memory scattered all over the place. Third, it isn't really needed. Launcher tasks can kick off workload tasks directly in their target cgroup. Using dedicated per-workload groups allows fine-grained policy adjustments - no need to move tasks and their physical pages between control domains. The feature was never forward-ported to cgroup2, and it hasn't been missed. Despite it being a niche usecase, the maintenance overhead of supporting it is enormous. Because pages are moved while they are live and subject to various MM operations, the synchronization rules are complicated. There are lock_page_memcg() in MM and FS code, which non-cgroup people don't understand. In some cases we've been able to shift code and cgroup API calls around such that we can rely on native locking as much as possible. But that's fragile, and sometimes we need to hold MM locks for longer than we otherwise would (pte lock e.g.). Mark the feature deprecated. Hopefully we can remove it soon. And backport into -stable kernels so that people who develop against earlier kernels are warned about this deprecation as early as possible. [akpm@linux-foundation.org: fix memory.rst underlining] Link: https://lkml.kernel.org/r/Y5COd+qXwk/S+n8N@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Aaron Thompson
|
1933be146c |
Revert "mm: Always release pages to the buddy allocator in memblock_free_late()."
commit 647037adcad00f2bab8828d3d41cd0553d41f3bd upstream.
This reverts commit 115d9d77bb0f9152c60b6e8646369fa7f6167593.
The pages being freed by memblock_free_late() have already been
initialized, but if they are in the deferred init range,
__free_one_page() might access nearby uninitialized pages when trying to
coalesce buddies. This can, for example, trigger this BUG:
BUG: unable to handle page fault for address: ffffe964c02580c8
RIP: 0010:__list_del_entry_valid+0x3f/0x70
<TASK>
__free_one_page+0x139/0x410
__free_pages_ok+0x21d/0x450
memblock_free_late+0x8c/0xb9
efi_free_boot_services+0x16b/0x25c
efi_enter_virtual_mode+0x403/0x446
start_kernel+0x678/0x714
secondary_startup_64_no_verify+0xd2/0xdb
</TASK>
A proper fix will be more involved so revert this change for the time
being.
Fixes: 115d9d77bb0f ("mm: Always release pages to the buddy allocator in memblock_free_late().")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
||
David Chen
|
0a626e27f9 |
Fix page corruption caused by racy check in __free_pages
commit 462a8e08e0e6287e5ce13187257edbf24213ed03 upstream. When we upgraded our kernel, we started seeing some page corruption like the following consistently: BUG: Bad page state in process ganesha.nfsd pfn:1304ca page:0000000022261c55 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x1304ca flags: 0x17ffffc0000000() raw: 0017ffffc0000000 ffff8a513ffd4c98 ffffeee24b35ec08 0000000000000000 raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000 page dumped because: nonzero mapcount CPU: 0 PID: 15567 Comm: ganesha.nfsd Kdump: loaded Tainted: P B O 5.10.158-1.nutanix.20221209.el7.x86_64 #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016 Call Trace: dump_stack+0x74/0x96 bad_page.cold+0x63/0x94 check_new_page_bad+0x6d/0x80 rmqueue+0x46e/0x970 get_page_from_freelist+0xcb/0x3f0 ? _cond_resched+0x19/0x40 __alloc_pages_nodemask+0x164/0x300 alloc_pages_current+0x87/0xf0 skb_page_frag_refill+0x84/0x110 ... Sometimes, it would also show up as corruption in the free list pointer and cause crashes. After bisecting the issue, we found the issue started from commit |
||
Mike Kravetz
|
dbe5a11954 |
migrate: hugetlb: check for hugetlb shared PMD in node migration
[ Upstream commit 73bdf65ea74857d7fb2ec3067a3cec0e261b1462 ]
migrate_pages/mempolicy semantics state that CAP_SYS_NICE is required to
move pages shared with another process to a different node. page_mapcount
> 1 is being used to determine if a hugetlb page is shared. However, a
hugetlb page will have a mapcount of 1 if mapped by multiple processes via
a shared PMD. As a result, hugetlb pages shared by multiple processes and
mapped with a shared PMD can be moved by a process without CAP_SYS_NICE.
To fix, check for a shared PMD if mapcount is 1. If a shared PMD is found
consider the page shared.
Link: https://lkml.kernel.org/r/20230126222721.222195-3-mike.kravetz@oracle.com
Fixes:
|
||
|
Miaohe Lin
|
97a5104d64 |
mm/migration: return errno when isolate_huge_page failed
[ Upstream commit 7ce82f4c3f3ead13a9d9498768e3b1a79975c4d8 ]
We might fail to isolate huge page due to e.g. the page is under
migration which cleared HPageMigratable. We should return errno in this
case rather than always return 1 which could confuse the user, i.e. the
caller might think all of the memory is migrated while the hugetlb page is
left behind. We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.
Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes:
|
||
Longlong Xia
|
30187be290 |
mm/swapfile: add cond_resched() in get_swap_pages()
commit 7717fc1a12f88701573f9ed897cc4f6699c661e3 upstream. The softlockup still occurs in get_swap_pages() under memory pressure. 64 CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram device is 50MB with same priority as si. Use the stress-ng tool to increase memory pressure, causing the system to oom frequently. The plist_for_each_entry_safe() loops in get_swap_pages() could reach tens of thousands of times to find available space (extreme case: cond_resched() is not called in scan_swap_map_slots()). Let's add cond_resched() into get_swap_pages() when failed to find available space to avoid softlockup. Link: https://lkml.kernel.org/r/20230128094757.1060525-1-xialonglong1@huawei.com Signed-off-by: Longlong Xia <xialonglong1@huawei.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Chen Wandun <chenwandun@huawei.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Kees Cook
|
55eba18262 |
panic: Consolidate open-coded panic_on_warn checks
commit 79cc1ba7badf9e7a12af99695a557e9ce27ee967 upstream. Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll their own warnings, and each check "panic_on_warn". Consolidate this into a single function so that future instrumentation can be added in a single location. Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Gow <davidgow@google.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: Jann Horn <jannh@google.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
Tiezhu Yang
|
715a63588f |
kasan: no need to unset panic_on_warn in end_report()
commit e7ce7500375a63348e1d3a703c8d5003cbe3fea6 upstream. panic_on_warn is unset inside panic(), so no need to unset it before calling panic() in end_report(). Link: https://lkml.kernel.org/r/1644324666-15947-6-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Xuefeng Li <lixuefeng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org> |
||
Hugh Dickins
|
8bc72b4952 |
mm/khugepaged: fix collapse_pte_mapped_thp() to allow anon_vma
commit ab0c3f1251b4670978fde0bd54161795a139b060 upstream. uprobe_write_opcode() uses collapse_pte_mapped_thp() to restore huge pmd, when removing a breakpoint from hugepage text: vma->anon_vma is always set in that case, so undo the prohibition. And MADV_COLLAPSE ought to be able to collapse some page tables in a vma which happens to have anon_vma set from CoWing elsewhere. Is anon_vma lock required? Almost not: if any page other than expected subpage of the non-anon huge page is found in the page table, collapse is aborted without making any change. However, it is possible that an anon page was CoWed from this extent in another mm or vma, in which case a concurrent lookup might look here: so keep it away while clearing pmd (but perhaps we shall go back to using pmd_lock() there in future). Note that collapse_pte_mapped_thp() is exceptional in freeing a page table without having cleared its ptes: I'm uneasy about that, and had thought pte_clear()ing appropriate; but exclusive i_mmap lock does fix the problem, and we would have to move the mmu_notification if clearing those ptes. What this fixes is not a dangerous instability. But I suggest Cc stable because uprobes "healing" has regressed in that way, so this should follow 8d3c106e19e8 into those stable releases where it was backported (and may want adjustment there - I'll supply backports as needed). Link: https://lkml.kernel.org/r/b740c9fb-edba-92ba-59fb-7a5592e5dfc@google.com Fixes: 8d3c106e19e8 ("mm/khugepaged: take the right locks for page table retraction") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: <stable@vger.kernel.org> [5.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Aaron Thompson
|
60806adc9b |
mm: Always release pages to the buddy allocator in memblock_free_late().
[ Upstream commit 115d9d77bb0f9152c60b6e8646369fa7f6167593 ]
If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
only releases pages to the buddy allocator if they are not in the
deferred range. This is correct for free pages (as defined by
for_each_free_mem_pfn_range_in_zone()) because free pages in the
deferred range will be initialized and released as part of the deferred
init process. memblock_free_pages() is called by memblock_free_late(),
which is used to free reserved ranges after memblock_free_all() has
run. All pages in reserved ranges have been initialized at that point,
and accordingly, those pages are not touched by the deferred init
process. This means that currently, if the pages that
memblock_free_late() intends to release are in the deferred range, they
will never be released to the buddy allocator. They will forever be
reserved.
In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
which is also correct for free pages but is not correct for reserved
pages. KMSAN metadata for reserved pages is initialized by
kmsan_init_shadow(), which runs shortly before memblock_free_all().
For both of these reasons, memblock_free_pages() should only be called
for free pages, and memblock_free_late() should call __free_pages_core()
directly instead.
One case where this issue can occur in the wild is EFI boot on
x86_64. The x86 EFI code reserves all EFI boot services memory ranges
via memblock_reserve() and frees them later via memblock_free_late()
(efi_reserve_boot_services() and efi_free_boot_services(),
respectively). If any of those ranges happens to fall within the
deferred init range, the pages will not be released and that memory will
be unavailable.
For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:
v6.2-rc2:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 178867
v6.2-rc2 + patch:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 222816 # +43,949 pages
Fixes:
|
||
NARIBAYASHI Akira
|
882734bbc5 |
mm, compaction: fix fast_isolate_around() to stay within boundaries
commit be21b32afe470c5ae98e27e49201158a47032942 upstream.
Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.
Panic can occur on systems with multiple zones in a single pageblock.
The reason it is rare is that it only happens in special
configurations. Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.
The problem is that pfn as argument of fast_isolate_around() could be out
of the target range. Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.
This problem should have been addressd by the commit 6e2b7044c199 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.
Case1: pfn < start_pfn
<at memory compaction for node Y>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ end_pfn
^ start_pfn = cc->zone->zone_start_pfn
pfn
<---------> scanned range by "Scan After"
Case2: end_pfn < pfn
<at memory compaction for node X>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ pfn
^ end_pfn
start_pfn
<---------> scanned range by "Scan Before"
It seems that there is no good reason to skip nr_isolated pages just after
given pfn. So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".
Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c199 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
||
Baolin Wang
|
fccee93eb2 |
mm/hugetlb: fix races when looking up a CONT-PTE/PMD size hugetlb page
commit fac35ba763ed07ba93154c95ffc0c4a55023707f upstream. On some architectures (like ARM64), it can support CONT-PTE/PMD size hugetlb, which means it can support not only PMD/PUD size hugetlb (2M and 1G), but also CONT-PTE/PMD size(64K and 32M) if a 4K page size specified. So when looking up a CONT-PTE size hugetlb page by follow_page(), it will use pte_offset_map_lock() to get the pte entry lock for the CONT-PTE size hugetlb in follow_page_pte(). However this pte entry lock is incorrect for the CONT-PTE size hugetlb, since we should use huge_pte_lock() to get the correct lock, which is mm->page_table_lock. That means the pte entry of the CONT-PTE size hugetlb under current pte lock is unstable in follow_page_pte(), we can continue to migrate or poison the pte entry of the CONT-PTE size hugetlb, which can cause some potential race issues, even though they are under the 'pte lock'. For example, suppose thread A is trying to look up a CONT-PTE size hugetlb page by move_pages() syscall under the lock, however antoher thread B can migrate the CONT-PTE hugetlb page at the same time, which will cause thread A to get an incorrect page, if thread A also wants to do page migration, then data inconsistency error occurs. Moreover we have the same issue for CONT-PMD size hugetlb in follow_huge_pmd(). To fix above issues, rename the follow_huge_pmd() as follow_huge_pmd_pte() to handle PMD and PTE level size hugetlb, which uses huge_pte_lock() to get the correct pte entry lock to make the pte entry stable. Mike said: Support for CONT_PMD/_PTE was added with |
||
John Starks
|
f1cf856123 |
mm/gup: fix gup_pud_range() for dax
commit fcd0ccd836ffad73d98a66f6fea7b16f735ea920 upstream. For dax pud, pud_huge() returns true on x86. So the function works as long as hugetlb is configured. However, dax doesn't depend on hugetlb. Commit |
||
Tejun Heo
|
f1f7f36cf6 |
memcg: fix possible use-after-free in memcg_write_event_control()
commit 4a7ba45b1a435e7097ca0f79a847d0949d0eb088 upstream. memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to |
||
Jann Horn
|
7f445ca2e0 |
mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths
commit f268f6cf875f3220afc77bdd0bf1bb136eb54db9 upstream. Any codepath that zaps page table entries must invoke MMU notifiers to ensure that secondary MMUs (like KVM) don't keep accessing pages which aren't mapped anymore. Secondary MMUs don't hold their own references to pages that are mirrored over, so failing to notify them can lead to page use-after-free. I'm marking this as addressing an issue introduced in commit |
||
|
Jann Horn
|
4a1cdb49d0 |
mm/khugepaged: fix GUP-fast interaction by sending IPI
commit 2ba99c5e08812494bc57f319fb562f527d9bacd8 upstream.
Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP
collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to
ensure that the page table was not removed by khugepaged in between.
However, lockless_pages_from_mm() still requires that the page table is
not concurrently freed. Fix it by sending IPIs (if the architecture uses
semi-RCU-style page table freeing) before freeing/reusing page tables.
Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com
Fixes:
|
||
|
Jann Horn
|
cdfd3739b2 |
mm/khugepaged: take the right locks for page table retraction
commit 8d3c106e19e8d251da31ff4cc7462e4565d65084 upstream.
pagetable walks on address ranges mapped by VMAs can be done under the
mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the
VMA's address_space. Only one of these needs to be held, and it does not
need to be held in exclusive mode.
Under those circumstances, the rules for concurrent access to page table
entries are:
- Terminal page table entries (entries that don't point to another page
table) can be arbitrarily changed under the page table lock, with the
exception that they always need to be consistent for
hardware page table walks and lockless_pages_from_mm().
This includes that they can be changed into non-terminal entries.
- Non-terminal page table entries (which point to another page table)
can not be modified; readers are allowed to READ_ONCE() an entry, verify
that it is non-terminal, and then assume that its value will stay as-is.
Retracting a page table involves modifying a non-terminal entry, so
page-table-level locks are insufficient to protect against concurrent page
table traversal; it requires taking all the higher-level locks under which
it is possible to start a page walk in the relevant range in exclusive
mode.
The collapse_huge_page() path for anonymous THP already follows this rule,
but the shmem/file THP path was getting it wrong, making it possible for
concurrent rmap-based operations to cause corruption.
Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com
Fixes:
|
||
Linus Torvalds
|
d072a10c81 |
v4l2: don't fall back to follow_pfn() if pin_user_pages_fast() fails
commit 6647e76ab623b2b3fb2efe03a86e9c9046c52c33 upstream.
The V4L2_MEMORY_USERPTR interface is long deprecated and shouldn't be
used (and is discouraged for any modern v4l drivers). And Seth Jenkins
points out that the fallback to VM_PFNMAP/VM_IO is fundamentally racy
and dangerous.
Note that it's not even a case that should trigger, since any normal
user pointer logic ends up just using the pin_user_pages_fast() call
that does the proper page reference counting. That's not the problem
case, only if you try to use special device mappings do you have any
issues.
Normally I'd just remove this during the merge window, but since Seth
pointed out the problem cases, we really want to know as soon as
possible if there are actually any users of this odd special case of a
legacy interface. Neither Hans nor Mauro seem to think that such
mis-uses of the old legacy interface should exist. As Mauro says:
"See, V4L2 has actually 4 streaming APIs:
- Kernel-allocated mmap (usually referred simply as just mmap);
- USERPTR mmap;
- read();
- dmabuf;
The USERPTR is one of the oldest way to use it, coming from V4L
version 1 times, and by far the least used one"
And Hans chimed in on the USERPTR interface:
"To be honest, I wouldn't mind if it goes away completely, but that's a
bit of a pipe dream right now"
but while removing this legacy interface entirely may be a pipe dream we
can at least try to remove the unlikely (and actively broken) case of
using special device mappings for USERPTR accesses.
This replaces it with a WARN_ONCE() that we can remove once we've
hopefully confirmed that no actual users exist.
NOTE! Longer term, this means that a 'struct frame_vector' only ever
contains proper page pointers, and all the games we have with converting
them to pages can go away (grep for 'frame_vector_to_pages()' and the
uses of 'vec->is_pfns'). But this is just the first step, to verify
that this code really is all dead, and do so as quickly as possible.
Reported-by: Seth Jenkins <sethjenkins@google.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
||
|
Johannes Weiner
|
d925dd3e44 |
mm: vmscan: fix extreme overreclaim and swap floods
commit f53af4285d775cd9a9a146fc438bd0a1bee1838a upstream.
During proactive reclaim, we sometimes observe severe overreclaim, with
several thousand times more pages reclaimed than requested.
This trace was obtained from shrink_lruvec() during such an instance:
prio:0 anon_cost:1141521 file_cost:7767
nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
nr=[7161123 345 578 1111]
While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
by swapping. These requests take over a minute, during which the write()
to memory.reclaim is unkillably stuck inside the kernel.
Digging into the source, this is caused by the proportional reclaim
bailout logic. This code tries to resolve a fundamental conflict: to
reclaim roughly what was requested, while also aging all LRUs fairly and
in accordance to their size, swappiness, refault rates etc. The way it
attempts fairness is that once the reclaim goal has been reached, it stops
scanning the LRUs with the smaller remaining scan targets, and adjusts the
remainder of the bigger LRUs according to how much of the smaller LRUs was
scanned. It then finishes scanning that remainder regardless of the
reclaim goal.
This works fine if priority levels are low and the LRU lists are
comparable in size. However, in this instance, the cgroup that is
targeted by proactive reclaim has almost no files left - they've already
been squeezed out by proactive reclaim earlier - and the remaining anon
pages are hot. Anon rotations cause the priority level to drop to 0,
which results in reclaim targeting all of anon (a lot) and all of file
(almost nothing). By the time reclaim decides to bail, it has scanned
most or all of the file target, and therefor must also scan most or all of
the enormous anon target. This target is thousands of times larger than
the reclaim goal, thus causing the overreclaim.
The bailout code hasn't changed in years, why is this failing now? The
most likely explanations are two other recent changes in anon reclaim:
1. Before the series starting with commit
|
||
Alexander Potapenko
|
294ef12dcc |
mm: fs: initialize fsdata passed to write_begin/write_end interface
commit 1468c6f4558b1bcd92aa0400f2920f9dc7588402 upstream. Functions implementing the a_ops->write_end() interface accept the `void *fsdata` parameter that is supposed to be initialized by the corresponding a_ops->write_begin() (which accepts `void **fsdata`). However not all a_ops->write_begin() implementations initialize `fsdata` unconditionally, so it may get passed uninitialized to a_ops->write_end(), resulting in undefined behavior. Fix this by initializing fsdata with NULL before the call to write_begin(), rather than doing so in all possible a_ops implementations. This patch covers only the following cases found by running x86 KMSAN under syzkaller: - generic_perform_write() - cont_expand_zero() and generic_cont_expand_simple() - page_symlink() Other cases of passing uninitialized fsdata may persist in the codebase. Link: https://lkml.kernel.org/r/20220915150417.722975-43-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
Alban Crequy
|
db744288af |
maccess: Fix writing offset in case of fault in strncpy_from_kernel_nofault()
commit 8678ea06852cd1f819b870c773d43df888d15d46 upstream.
If a page fault occurs while copying the first byte, this function resets one
byte before dst.
As a consequence, an address could be modified and leaded to kernel crashes if
case the modified address was accessed later.
Fixes:
|
||
Pankaj Gupta
|
0b692d41ee |
mm/memremap.c: map FS_DAX device memory as decrypted
commit 867400af90f1f953ff9e10b1b87ecaf9369a7eb8 upstream.
virtio_pmem use devm_memremap_pages() to map the device memory. By
default this memory is mapped as encrypted with SEV. Guest reboot changes
the current encryption key and guest no longer properly decrypts the FSDAX
device meta data.
Mark the corresponding device memory region for FSDAX devices (mapped with
memremap_pages) as decrypted to retain the persistent memory property.
Link: https://lkml.kernel.org/r/20221102160728.3184016-1-pankaj.gupta@amd.com
Fixes:
|
||
Rik van Riel
|
568e3812b1 |
mm,hugetlb: take hugetlb_lock before decrementing h->resv_huge_pages
commit 12df140f0bdfae5dcfc81800970dd7f6f632e00c upstream.
The h->*_huge_pages counters are protected by the hugetlb_lock, but
alloc_huge_page has a corner case where it can decrement the counter
outside of the lock.
This could lead to a corrupted value of h->resv_huge_pages, which we have
observed on our systems.
Take the hugetlb_lock before decrementing h->resv_huge_pages to avoid a
potential race.
Link: https://lkml.kernel.org/r/20221017202505.0e6a4fcd@imladris.surriel.com
Fixes:
|
||
Yuanzheng Song
|
935a8b6202 |
mm/memory: add non-anonymous page check in the copy_present_page()
The vma->anon_vma of the child process may be NULL because
the entire vma does not contain anonymous pages. In this
case, a BUG will occur when the copy_present_page() passes
a copy of a non-anonymous page of that vma to the
page_add_new_anon_rmap() to set up new anonymous rmap.
------------[ cut here ]------------
kernel BUG at mm/rmap.c:1044!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in:
CPU: 2 PID: 3617 Comm: test Not tainted 5.10.149 #1
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
pc : __page_set_anon_rmap+0xbc/0xf8
lr : __page_set_anon_rmap+0xbc/0xf8
sp : ffff800014c1b870
x29: ffff800014c1b870 x28: 0000000000000001
x27: 0000000010100073 x26: ffff1d65c517baa8
x25: ffff1d65cab0f000 x24: ffff1d65c416d800
x23: ffff1d65cab5f248 x22: 0000000020000000
x21: 0000000000000001 x20: 0000000000000000
x19: fffffe75970023c0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000
x15: 0000000000000000 x14: 0000000000000000
x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000
x9 : ffffc3096d5fb858 x8 : 0000000000000000
x7 : 0000000000000011 x6 : ffff5a5c9089c000
x5 : 0000000000020000 x4 : ffff5a5c9089c000
x3 : ffffc3096d200000 x2 : ffffc3096e8d0000
x1 : ffff1d65ca3da740 x0 : 0000000000000000
Call trace:
__page_set_anon_rmap+0xbc/0xf8
page_add_new_anon_rmap+0x1e0/0x390
copy_pte_range+0xd00/0x1248
copy_page_range+0x39c/0x620
dup_mmap+0x2e0/0x5a8
dup_mm+0x78/0x140
copy_process+0x918/0x1a20
kernel_clone+0xac/0x638
__do_sys_clone+0x78/0xb0
__arm64_sys_clone+0x30/0x40
el0_svc_common.constprop.0+0xb0/0x308
do_el0_svc+0x48/0xb8
el0_svc+0x24/0x38
el0_sync_handler+0x160/0x168
el0_sync+0x180/0x1c0
Code: 97f8ff85 f9400294 17ffffeb 97f8ff82 (d4210000)
---[ end trace a972347688dc9bd4 ]---
Kernel panic - not syncing: Oops - BUG: Fatal exception
SMP: stopping secondary CPUs
Kernel Offset: 0x43095d200000 from 0xffff800010000000
PHYS_OFFSET: 0xffffe29a80000000
CPU features: 0x08200022,61806082
Memory Limit: none
---[ end Kernel panic - not syncing: Oops - BUG: Fatal exception ]---
This problem has been fixed by the commit <fb3d824d1a46>
("mm/rmap: split page_dup_rmap() into page_dup_file_rmap()
and page_try_dup_anon_rmap()"), but still exists in the
linux-5.10.y branch.
This patch is not applicable to this version because
of the large version differences. Therefore, fix it by
adding non-anonymous page check in the copy_present_page().
Cc: stable@vger.kernel.org
Fixes:
|
||
Liu Shixin
|
45c3396675 |
mm: hugetlb: fix UAF in hugetlb_handle_userfault
commit 958f32ce832ba781ac20e11bb2d12a9352ea28fc upstream.
The vma_lock and hugetlb_fault_mutex are dropped before handling userfault
and reacquire them again after handle_userfault(), but reacquire the
vma_lock could lead to UAF[1,2] due to the following race,
hugetlb_fault
hugetlb_no_page
/*unlock vma_lock */
hugetlb_handle_userfault
handle_userfault
/* unlock mm->mmap_lock*/
vm_mmap_pgoff
do_mmap
mmap_region
munmap_vma_range
/* clean old vma */
/* lock vma_lock again <--- UAF */
/* unlock vma_lock */
Since the vma_lock will unlock immediately after
hugetlb_handle_userfault(), let's drop the unneeded lock and unlock in
hugetlb_handle_userfault() to fix the issue.
[1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/
[2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/
Link: https://lkml.kernel.org/r/20220923042113.137273-1-liushixin2@huawei.com
Fixes:
|
||
Carlos Llamas
|
a3c08c0217 |
mm/mmap: undo ->mmap() when arch_validate_flags() fails
commit deb0f6562884b5b4beb883d73e66a7d3a1b96d99 upstream. Commit |
||
Yang Shi
|
377c60dd32 |
mm: gup: fix the fast GUP race against THP collapse
commit 70cbc3cc78a997d8247b50389d37c4e1736019da upstream. Since general RCU GUP fast was introduced in commit |
||
Minchan Kim
|
be2cd261ca |
mm: fix madivse_pageout mishandling on non-LRU page
commit 58d426a7ba92870d489686dfdb9d06b66815a2ab upstream.
MADV_PAGEOUT tries to isolate non-LRU pages and gets a warning from
isolate_lru_page below.
Fix it by checking PageLRU in advance.
------------[ cut here ]------------
trying to isolate tail page
WARNING: CPU: 0 PID: 6175 at mm/folio-compat.c:158 isolate_lru_page+0x130/0x140
Modules linked in:
CPU: 0 PID: 6175 Comm: syz-executor.0 Not tainted 5.18.12 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:isolate_lru_page+0x130/0x140
Link: https://lore.kernel.org/linux-mm/485f8c33.2471b.182d5726afb.Coremail.hantianshuo@iie.ac.cn/
Link: https://lkml.kernel.org/r/20220908151204.762596-1-minchan@kernel.org
Fixes:
|
||
Alistair Popple
|
1002d5fef4 |
mm/migrate_device.c: flush TLB while holding PTL
commit 60bae73708963de4a17231077285bd9ff2f41c44 upstream.
When clearing a PTE the TLB should be flushed whilst still holding the PTL
to avoid a potential race with madvise/munmap/etc. For example consider
the following sequence:
CPU0 CPU1
---- ----
migrate_vma_collect_pmd()
pte_unmap_unlock()
madvise(MADV_DONTNEED)
-> zap_pte_range()
pte_offset_map_lock()
[ PTE not present, TLB not flushed ]
pte_unmap_unlock()
[ page is still accessible via stale TLB ]
flush_tlb_range()
In this case the page may still be accessed via the stale TLB entry after
madvise returns. Fix this by flushing the TLB while holding the PTL.
Fixes:
|
||
Maurizio Lombardi
|
a54fc53691 |
mm: prevent page_frag_alloc() from corrupting the memory
commit dac22531bbd4af2426c4e29e05594415ccfa365d upstream.
A number of drivers call page_frag_alloc() with a fragment's size >
PAGE_SIZE.
In low memory conditions, __page_frag_cache_refill() may fail the order
3 cache allocation and fall back to order 0; In this case, the cache
will be smaller than the fragment, causing memory corruptions.
Prevent this from happening by checking if the newly allocated cache is
large enough for the fragment; if not, the allocation will fail and
page_frag_alloc() will return NULL.
Link: https://lkml.kernel.org/r/20220715125013.247085-1-mlombard@redhat.com
Fixes:
|
||
Mel Gorman
|
466a26af2d |
mm/page_alloc: fix race condition between build_all_zonelists and page allocation
commit 3d36424b3b5850bd92f3e89b953a430d7cfc88ef upstream. Patrick Daly reported the following problem; NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - before offline operation [0] - ZONE_MOVABLE [1] - ZONE_NORMAL [2] - NULL For a GFP_KERNEL allocation, alloc_pages_slowpath() will save the offset of ZONE_NORMAL in ac->preferred_zoneref. If a concurrent memory_offline operation removes the last page from ZONE_MOVABLE, build_all_zonelists() & build_zonerefs_node() will update node_zonelists as shown below. Only populated zones are added. NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - after offline operation [0] - ZONE_NORMAL [1] - NULL [2] - NULL The race is simple -- page allocation could be in progress when a memory hot-remove operation triggers a zonelist rebuild that removes zones. The allocation request will still have a valid ac->preferred_zoneref that is now pointing to NULL and triggers an OOM kill. This problem probably always existed but may be slightly easier to trigger due to |
||
Chao Yu
|
379ac7905f |
mm/slub: fix to return errno if kmalloc() fails
commit 7e9c323c52b379d261a72dc7bd38120a761a93cd upstream.
In create_unique_id(), kmalloc(, GFP_KERNEL) can fail due to
out-of-memory, if it fails, return errno correctly rather than
triggering panic via BUG_ON();
kernel BUG at mm/slub.c:5893!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Call trace:
sysfs_slab_add+0x258/0x260 mm/slub.c:5973
__kmem_cache_create+0x60/0x118 mm/slub.c:4899
create_cache mm/slab_common.c:229 [inline]
kmem_cache_create_usercopy+0x19c/0x31c mm/slab_common.c:335
kmem_cache_create+0x1c/0x28 mm/slab_common.c:390
f2fs_kmem_cache_create fs/f2fs/f2fs.h:2766 [inline]
f2fs_init_xattr_caches+0x78/0xb4 fs/f2fs/xattr.c:808
f2fs_fill_super+0x1050/0x1e0c fs/f2fs/super.c:4149
mount_bdev+0x1b8/0x210 fs/super.c:1400
f2fs_mount+0x44/0x58 fs/f2fs/super.c:4512
legacy_get_tree+0x30/0x74 fs/fs_context.c:610
vfs_get_tree+0x40/0x140 fs/super.c:1530
do_new_mount+0x1dc/0x4e4 fs/namespace.c:3040
path_mount+0x358/0x914 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__arm64_sys_mount+0x2f8/0x408 fs/namespace.c:3568
Cc: <stable@kernel.org>
Fixes:
|
||
|
Jann Horn
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891f03f688 |
mm: Fix TLB flush for not-first PFNMAP mappings in unmap_region()
This is a stable-specific patch.
I botched the stable-specific rewrite of
commit b67fbebd4cf98 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas"):
As Hugh pointed out, unmap_region() actually operates on a list of VMAs,
and the variable "vma" merely points to the first VMA in that list.
So if we want to check whether any of the VMAs we're operating on is
PFNMAP or MIXEDMAP, we have to iterate through the list and check each VMA.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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