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Kuniyuki Iwashima cf29b42766 af_unix: Fix data-race around unix_tot_inflight.
[ Upstream commit ade32bd8a738d7497ffe9743c46728db26740f78 ]

unix_tot_inflight is changed under spin_lock(unix_gc_lock), but
unix_release_sock() reads it locklessly.

Let's use READ_ONCE() for unix_tot_inflight.

Note that the writer side was marked by commit 9d6d7f1cb67c ("af_unix:
annote lockless accesses to unix_tot_inflight & gc_in_progress")

BUG: KCSAN: data-race in unix_inflight / unix_release_sock

write (marked) to 0xffffffff871852b8 of 4 bytes by task 123 on cpu 1:
 unix_inflight+0x130/0x180 net/unix/scm.c:64
 unix_attach_fds+0x137/0x1b0 net/unix/scm.c:123
 unix_scm_to_skb net/unix/af_unix.c:1832 [inline]
 unix_dgram_sendmsg+0x46a/0x14f0 net/unix/af_unix.c:1955
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x148/0x160 net/socket.c:747
 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2493
 ___sys_sendmsg+0xc6/0x140 net/socket.c:2547
 __sys_sendmsg+0x94/0x140 net/socket.c:2576
 __do_sys_sendmsg net/socket.c:2585 [inline]
 __se_sys_sendmsg net/socket.c:2583 [inline]
 __x64_sys_sendmsg+0x45/0x50 net/socket.c:2583
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffffffff871852b8 of 4 bytes by task 4891 on cpu 0:
 unix_release_sock+0x608/0x910 net/unix/af_unix.c:671
 unix_release+0x59/0x80 net/unix/af_unix.c:1058
 __sock_release+0x7d/0x170 net/socket.c:653
 sock_close+0x19/0x30 net/socket.c:1385
 __fput+0x179/0x5e0 fs/file_table.c:321
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x116/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297
 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4891 Comm: systemd-coredum Not tainted 6.4.0-rc5-01219-gfa0e21fa4443 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 9305cfa444 ("[AF_UNIX]: Make unix_tot_inflight counter non-atomic")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:20:26 +02:00
arch x86/virt: Drop unnecessary check on extended CPUID level in cpu_has_svm() 2023-09-19 12:20:25 +02:00
block block/partition: fix signedness issue for Amiga partitions 2023-07-27 08:44:18 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:13:17 +02:00
crypto X.509: if signature is unsupported skip validation 2023-09-19 12:20:22 +02:00
Documentation dt-bindings: clock: xlnx,versal-clk: drop select:false 2023-09-19 12:20:24 +02:00
drivers veth: Fixing transmit return status for dropped packets 2023-09-19 12:20:26 +02:00
fs NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info 2023-09-19 12:20:25 +02:00
include ipv4: ignore dst hint for multipath routes 2023-09-19 12:20:26 +02:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:57:39 +02:00
io_uring io_uring: break iopolling on signal 2023-09-19 12:20:24 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:24:00 +01:00
kernel tracing: Zero the pipe cpumask on alloc to avoid spurious -EBUSY 2023-09-19 12:20:23 +02:00
lib lib/test_meminit: allocate pages up to order MAX_ORDER 2023-09-19 12:20:24 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm tmpfs: verify {g,u}id mount options correctly 2023-09-19 12:20:06 +02:00
net af_unix: Fix data-race around unix_tot_inflight. 2023-09-19 12:20:26 +02:00
samples samples/bpf: fix broken map lookup probe 2023-09-19 12:20:09 +02:00
scripts kconfig: fix possible buffer overflow 2023-09-19 12:20:25 +02:00
security smackfs: Prevent underflow in smk_set_cipso() 2023-09-19 12:20:13 +02:00
sound ALSA: pcm: Fix missing fixup call in compat hw_refine ioctl 2023-09-19 12:20:21 +02:00
tools perf top: Don't pass an ERR_PTR() directly to perf_session__delete() 2023-09-19 12:20:25 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: fix memoryleak in kvm_init() 2023-04-05 11:23:43 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Remove DECnet support from kernel 2023-06-21 15:45:38 +02:00
Makefile Linux 5.10.194 2023-09-02 09:18:14 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.