Commit Graph

3774 Commits

Author SHA1 Message Date
Russell Harmon via samba-technical
6e74926ede cifs: Release folio lock on fscache read hit.
commit 69513dd669e243928f7450893190915a88f84a2b upstream.

Under the current code, when cifs_readpage_worker is called, the call
contract is that the callee should unlock the page. This is documented
in the read_folio section of Documentation/filesystems/vfs.rst as:

> The filesystem should unlock the folio once the read has completed,
> whether it was successful or not.

Without this change, when fscache is in use and cache hit occurs during
a read, the page lock is leaked, producing the following stack on
subsequent reads (via mmap) to the page:

$ cat /proc/3890/task/12864/stack
[<0>] folio_wait_bit_common+0x124/0x350
[<0>] filemap_read_folio+0xad/0xf0
[<0>] filemap_fault+0x8b1/0xab0
[<0>] __do_fault+0x39/0x150
[<0>] do_fault+0x25c/0x3e0
[<0>] __handle_mm_fault+0x6ca/0xc70
[<0>] handle_mm_fault+0xe9/0x350
[<0>] do_user_addr_fault+0x225/0x6c0
[<0>] exc_page_fault+0x84/0x1b0
[<0>] asm_exc_page_fault+0x27/0x30

This requires a reboot to resolve; it is a deadlock.

Note however that the call to cifs_readpage_from_fscache does mark the
page clean, but does not free the folio lock. This happens in
__cifs_readpage_from_fscache on success. Releasing the lock at that
point however is not appropriate as cifs_readahead also calls
cifs_readpage_from_fscache and *does* unconditionally release the lock
after its return. This change therefore effectively makes
cifs_readpage_worker work like cifs_readahead.

Signed-off-by: Russell Harmon <russ@har.mn>
Acked-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-26 15:26:55 +02:00
Pawel Witek
8c2cdb7326 cifs: fix pcchunk length type in smb2_copychunk_range
commit d66cde50c3c868af7abddafce701bb86e4a93039 upstream.

Change type of pcchunk->Length from u32 to u64 to match
smb2_copychunk_range arguments type. Fixes the problem where performing
server-side copy with CIFS_IOC_COPYCHUNK_FILE ioctl resulted in incomplete
copy of large files while returning -EINVAL.

Fixes: 9bf0c9cd43 ("CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files")
Cc: <stable@vger.kernel.org>
Signed-off-by: Pawel Witek <pawel.ireneusz.witek@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-17 11:48:14 +02:00
David Disseldorp
26a32a212b cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL
commit 179a88a8558bbf42991d361595281f3e45d7edfc upstream.

When compiled with CONFIG_CIFS_DFS_UPCALL disabled, cifs_dfs_d_automount
is NULL. cifs.ko logic for mapping CIFS_FATTR_DFS_REFERRAL attributes to
S_AUTOMOUNT and corresponding dentry flags is retained regardless of
CONFIG_CIFS_DFS_UPCALL, leading to a NULL pointer dereference in
VFS follow_automount() when traversing a DFS referral link:
  BUG: kernel NULL pointer dereference, address: 0000000000000000
  ...
  Call Trace:
   <TASK>
   __traverse_mounts+0xb5/0x220
   ? cifs_revalidate_mapping+0x65/0xc0 [cifs]
   step_into+0x195/0x610
   ? lookup_fast+0xe2/0xf0
   path_lookupat+0x64/0x140
   filename_lookup+0xc2/0x140
   ? __create_object+0x299/0x380
   ? kmem_cache_alloc+0x119/0x220
   ? user_path_at_empty+0x31/0x50
   user_path_at_empty+0x31/0x50
   __x64_sys_chdir+0x2a/0xd0
   ? exit_to_user_mode_prepare+0xca/0x100
   do_syscall_64+0x42/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

This fix adds an inline cifs_dfs_d_automount() {return -EREMOTE} handler
when CONFIG_CIFS_DFS_UPCALL is disabled. An alternative would be to
avoid flagging S_AUTOMOUNT, etc. without CONFIG_CIFS_DFS_UPCALL. This
approach was chosen as it provides more control over the error path.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:23:49 +02:00
Paulo Alcantara
63bbe24b99 cifs: prevent infinite recursion in CIFSGetDFSRefer()
commit 09ba47b44d26b475bbdf9c80db9e0193d2b58956 upstream.

We can't call smb_init() in CIFSGetDFSRefer() as cifs_reconnect_tcon()
may end up calling CIFSGetDFSRefer() again to get new DFS referrals
and thus causing an infinite recursion.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Cc: stable@vger.kernel.org # 6.2
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:23:49 +02:00
Shyam Prasad N
f7a4ce3514 cifs: empty interface list when server doesn't support query interfaces
commit 896cd316b841053f6df95ab77b5f1322c16a8e18 upstream.

When querying server interfaces returns -EOPNOTSUPP,
clear the list of interfaces. Assumption is that multichannel
would be disabled too.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:23:39 +02:00
Volker Lendecke
7b18dea697 cifs: Fix smb2_set_path_size()
commit 211baef0eabf4169ce4f73ebd917749d1a7edd74 upstream.

If cifs_get_writable_path() finds a writable file, smb2_compound_op()
must use that file's FID and not the COMPOUND_FID.

Cc: stable@vger.kernel.org
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-22 13:30:03 +01:00
Zhang Xiaoxu
ed9ed2f58c cifs: Move the in_send statistic to __smb_send_rqst()
[ Upstream commit d0dc41119905f740e8d5594adce277f7c0de8c92 ]

When send SMB_COM_NT_CANCEL and RFC1002_SESSION_REQUEST, the
in_send statistic was lost.

Let's move the in_send statistic to the send function to avoid
this scenario.

Fixes: 7ee1af765d ("[CIFS]")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-22 13:29:55 +01:00
Volker Lendecke
69493675fd cifs: Fix uninitialized memory read in smb3_qfs_tcon()
commit d447e794a37288ec7a080aa1b044a8d9deebbab7 upstream.

oparms was not fully initialized

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 16:39:55 +01:00
Zhang Xiaoxu
cfd85a0922 cifs: Fix warning and UAF when destroy the MR list
[ Upstream commit 3e161c2791f8e661eed24a2c624087084d910215 ]

If the MR allocate failed, the MR recovery work not initialized
and list not cleared. Then will be warning and UAF when release
the MR:

  WARNING: CPU: 4 PID: 824 at kernel/workqueue.c:3066 __flush_work.isra.0+0xf7/0x110
  CPU: 4 PID: 824 Comm: mount.cifs Not tainted 6.1.0-rc5+ #82
  RIP: 0010:__flush_work.isra.0+0xf7/0x110
  Call Trace:
   <TASK>
   __cancel_work_timer+0x2ba/0x2e0
   smbd_destroy+0x4e1/0x990
   _smbd_get_connection+0x1cbd/0x2110
   smbd_get_connection+0x21/0x40
   cifs_get_tcp_session+0x8ef/0xda0
   mount_get_conns+0x60/0x750
   cifs_mount+0x103/0xd00
   cifs_smb3_do_mount+0x1dd/0xcb0
   smb3_get_tree+0x1d5/0x300
   vfs_get_tree+0x41/0xf0
   path_mount+0x9b3/0xdd0
   __x64_sys_mount+0x190/0x1d0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

  BUG: KASAN: use-after-free in smbd_destroy+0x4fc/0x990
  Read of size 8 at addr ffff88810b156a08 by task mount.cifs/824
  CPU: 4 PID: 824 Comm: mount.cifs Tainted: G        W          6.1.0-rc5+ #82
  Call Trace:
   dump_stack_lvl+0x34/0x44
   print_report+0x171/0x472
   kasan_report+0xad/0x130
   smbd_destroy+0x4fc/0x990
   _smbd_get_connection+0x1cbd/0x2110
   smbd_get_connection+0x21/0x40
   cifs_get_tcp_session+0x8ef/0xda0
   mount_get_conns+0x60/0x750
   cifs_mount+0x103/0xd00
   cifs_smb3_do_mount+0x1dd/0xcb0
   smb3_get_tree+0x1d5/0x300
   vfs_get_tree+0x41/0xf0
   path_mount+0x9b3/0xdd0
   __x64_sys_mount+0x190/0x1d0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

  Allocated by task 824:
   kasan_save_stack+0x1e/0x40
   kasan_set_track+0x21/0x30
   __kasan_kmalloc+0x7a/0x90
   _smbd_get_connection+0x1b6f/0x2110
   smbd_get_connection+0x21/0x40
   cifs_get_tcp_session+0x8ef/0xda0
   mount_get_conns+0x60/0x750
   cifs_mount+0x103/0xd00
   cifs_smb3_do_mount+0x1dd/0xcb0
   smb3_get_tree+0x1d5/0x300
   vfs_get_tree+0x41/0xf0
   path_mount+0x9b3/0xdd0
   __x64_sys_mount+0x190/0x1d0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

  Freed by task 824:
   kasan_save_stack+0x1e/0x40
   kasan_set_track+0x21/0x30
   kasan_save_free_info+0x2a/0x40
   ____kasan_slab_free+0x143/0x1b0
   __kmem_cache_free+0xc8/0x330
   _smbd_get_connection+0x1c6a/0x2110
   smbd_get_connection+0x21/0x40
   cifs_get_tcp_session+0x8ef/0xda0
   mount_get_conns+0x60/0x750
   cifs_mount+0x103/0xd00
   cifs_smb3_do_mount+0x1dd/0xcb0
   smb3_get_tree+0x1d5/0x300
   vfs_get_tree+0x41/0xf0
   path_mount+0x9b3/0xdd0
   __x64_sys_mount+0x190/0x1d0
   do_syscall_64+0x35/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

Let's initialize the MR recovery work before MR allocate to prevent
the warning, remove the MRs from the list to prevent the UAF.

Fixes: c739858334 ("CIFS: SMBD: Implement RDMA memory registration")
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:39:39 +01:00
Zhang Xiaoxu
caac205e0d cifs: Fix lost destroy smbd connection when MR allocate failed
[ Upstream commit e9d3401d95d62a9531082cd2453ed42f2740e3fd ]

If the MR allocate failed, the smb direct connection info is NULL,
then smbd_destroy() will directly return, then the connection info
will be leaked.

Let's set the smb direct connection info to the server before call
smbd_destroy().

Fixes: c739858334 ("CIFS: SMBD: Implement RDMA memory registration")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:39:39 +01:00
ZhaoLong Wang
2b693fe3f7 cifs: Fix use-after-free in rdata->read_into_pages()
commit aa5465aeca3c66fecdf7efcf554aed79b4c4b211 upstream.

When the network status is unstable, use-after-free may occur when
read data from the server.

  BUG: KASAN: use-after-free in readpages_fill_pages+0x14c/0x7e0

  Call Trace:
   <TASK>
   dump_stack_lvl+0x38/0x4c
   print_report+0x16f/0x4a6
   kasan_report+0xb7/0x130
   readpages_fill_pages+0x14c/0x7e0
   cifs_readv_receive+0x46d/0xa40
   cifs_demultiplex_thread+0x121c/0x1490
   kthread+0x16b/0x1a0
   ret_from_fork+0x2c/0x50
   </TASK>

  Allocated by task 2535:
   kasan_save_stack+0x22/0x50
   kasan_set_track+0x25/0x30
   __kasan_kmalloc+0x82/0x90
   cifs_readdata_direct_alloc+0x2c/0x110
   cifs_readdata_alloc+0x2d/0x60
   cifs_readahead+0x393/0xfe0
   read_pages+0x12f/0x470
   page_cache_ra_unbounded+0x1b1/0x240
   filemap_get_pages+0x1c8/0x9a0
   filemap_read+0x1c0/0x540
   cifs_strict_readv+0x21b/0x240
   vfs_read+0x395/0x4b0
   ksys_read+0xb8/0x150
   do_syscall_64+0x3f/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

  Freed by task 79:
   kasan_save_stack+0x22/0x50
   kasan_set_track+0x25/0x30
   kasan_save_free_info+0x2e/0x50
   __kasan_slab_free+0x10e/0x1a0
   __kmem_cache_free+0x7a/0x1a0
   cifs_readdata_release+0x49/0x60
   process_one_work+0x46c/0x760
   worker_thread+0x2a4/0x6f0
   kthread+0x16b/0x1a0
   ret_from_fork+0x2c/0x50

  Last potentially related work creation:
   kasan_save_stack+0x22/0x50
   __kasan_record_aux_stack+0x95/0xb0
   insert_work+0x2b/0x130
   __queue_work+0x1fe/0x660
   queue_work_on+0x4b/0x60
   smb2_readv_callback+0x396/0x800
   cifs_abort_connection+0x474/0x6a0
   cifs_reconnect+0x5cb/0xa50
   cifs_readv_from_socket.cold+0x22/0x6c
   cifs_read_page_from_socket+0xc1/0x100
   readpages_fill_pages.cold+0x2f/0x46
   cifs_readv_receive+0x46d/0xa40
   cifs_demultiplex_thread+0x121c/0x1490
   kthread+0x16b/0x1a0
   ret_from_fork+0x2c/0x50

The following function calls will cause UAF of the rdata pointer.

readpages_fill_pages
 cifs_read_page_from_socket
  cifs_readv_from_socket
   cifs_reconnect
    __cifs_reconnect
     cifs_abort_connection
      mid->callback() --> smb2_readv_callback
       queue_work(&rdata->work)  # if the worker completes first,
                                 # the rdata is freed
          cifs_readv_complete
            kref_put
              cifs_readdata_release
                kfree(rdata)
 return rdata->...               # UAF in readpages_fill_pages()

Similarly, this problem also occurs in the uncache_fill_pages().

Fix this by adjusts the order of condition judgment in the return
statement.

Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Cc: stable@vger.kernel.org
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-15 17:22:26 +01:00
David Howells
e037baee16 cifs: Fix oops due to uncleared server->smbd_conn in reconnect
commit b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7 upstream.

In smbd_destroy(), clear the server->smbd_conn pointer after freeing the
smbd_connection struct that it points to so that reconnection doesn't get
confused.

Fixes: 8ef130f9ec ("CIFS: SMBD: Implement function to destroy a SMB Direct connection")
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Long Li <longli@microsoft.com>
Cc: Pavel Shilovsky <piastryyy@gmail.com>
Cc: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-01 08:23:22 +01:00
Enzo Matsumiya
531268a875 cifs: do not include page data when checking signature
commit 30b2b2196d6e4cc24cbec633535a2404f258ce69 upstream.

On async reads, page data is allocated before sending.  When the
response is received but it has no data to fill (e.g.
STATUS_END_OF_FILE), __calc_signature() will still include the pages in
its computation, leading to an invalid signature check.

This patch fixes this by not setting the async read smb_rqst page data
(zeroed by default) if its got_bytes is 0.

This can be reproduced/verified with xfstests generic/465.

Cc: <stable@vger.kernel.org>
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24 07:19:59 +01:00
Volker Lendecke
afb6063aa8 cifs: Fix uninitialized memory read for smb311 posix symlink create
commit a152d05ae4a71d802d50cf9177dba34e8bb09f68 upstream.

If smb311 posix is enabled, we send the intended mode for file
creation in the posix create context. Instead of using what's there on
the stack, create the mfsymlink file with 0644.

Fixes: ce558b0e17 ("smb3: Add posix create context for smb3.11 posix mounts")
Cc: stable@vger.kernel.org
Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 11:44:54 +01:00
Steve French
6155aed476 cifs: fix missing display of three mount options
commit 2bfd81043e944af0e52835ef6d9b41795af22341 upstream.

Three mount options: "tcpnodelay" and "noautotune" and "noblocksend"
were not displayed when passed in on cifs/smb3 mounts (e.g. displayed
in /proc/mounts e.g.).  No change to defaults so these are not
displayed if not specified on mount.

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:34 +01:00
Paulo Alcantara
8c82733e24 cifs: fix confusing debug message
commit a85ceafd41927e41a4103d228a993df7edd8823b upstream.

Since rc was initialised to -ENOMEM in cifs_get_smb_ses(), when an
existing smb session was found, free_xid() would be called and then
print

  CIFS: fs/cifs/connect.c: Existing tcp session with server found
  CIFS: fs/cifs/connect.c: VFS: in cifs_get_smb_ses as Xid: 44 with uid: 0
  CIFS: fs/cifs/connect.c: Existing smb sess found (status=1)
  CIFS: fs/cifs/connect.c: VFS: leaving cifs_get_smb_ses (xid = 44) rc = -12

Fix this by initialising rc to 0 and then let free_xid() print this
instead

  CIFS: fs/cifs/connect.c: Existing tcp session with server found
  CIFS: fs/cifs/connect.c: VFS: in cifs_get_smb_ses as Xid: 14 with uid: 0
  CIFS: fs/cifs/connect.c: Existing smb sess found (status=1)
  CIFS: fs/cifs/connect.c: VFS: leaving cifs_get_smb_ses (xid = 14) rc = 0

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-14 10:16:34 +01:00
Paulo Alcantara
fe6ea044c4 cifs: fix oops during encryption
[ Upstream commit f7f291e14dde32a07b1f0aa06921d28f875a7b54 ]

When running xfstests against Azure the following oops occurred on an
arm64 system

  Unable to handle kernel write to read-only memory at virtual address
  ffff0001221cf000
  Mem abort info:
    ESR = 0x9600004f
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
    FSC = 0x0f: level 3 permission fault
  Data abort info:
    ISV = 0, ISS = 0x0000004f
    CM = 0, WnR = 1
  swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000294f3000
  [ffff0001221cf000] pgd=18000001ffff8003, p4d=18000001ffff8003,
  pud=18000001ff82e003, pmd=18000001ff71d003, pte=00600001221cf787
  Internal error: Oops: 9600004f [#1] PREEMPT SMP
  ...
  pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
  pc : __memcpy+0x40/0x230
  lr : scatterwalk_copychunks+0xe0/0x200
  sp : ffff800014e92de0
  x29: ffff800014e92de0 x28: ffff000114f9de80 x27: 0000000000000008
  x26: 0000000000000008 x25: ffff800014e92e78 x24: 0000000000000008
  x23: 0000000000000001 x22: 0000040000000000 x21: ffff000000000000
  x20: 0000000000000001 x19: ffff0001037c4488 x18: 0000000000000014
  x17: 235e1c0d6efa9661 x16: a435f9576b6edd6c x15: 0000000000000058
  x14: 0000000000000001 x13: 0000000000000008 x12: ffff000114f2e590
  x11: ffffffffffffffff x10: 0000040000000000 x9 : ffff8000105c3580
  x8 : 2e9413b10000001a x7 : 534b4410fb86b005 x6 : 534b4410fb86b005
  x5 : ffff0001221cf008 x4 : ffff0001037c4490 x3 : 0000000000000001
  x2 : 0000000000000008 x1 : ffff0001037c4488 x0 : ffff0001221cf000
  Call trace:
   __memcpy+0x40/0x230
   scatterwalk_map_and_copy+0x98/0x100
   crypto_ccm_encrypt+0x150/0x180
   crypto_aead_encrypt+0x2c/0x40
   crypt_message+0x750/0x880
   smb3_init_transform_rq+0x298/0x340
   smb_send_rqst.part.11+0xd8/0x180
   smb_send_rqst+0x3c/0x100
   compound_send_recv+0x534/0xbc0
   smb2_query_info_compound+0x32c/0x440
   smb2_set_ea+0x438/0x4c0
   cifs_xattr_set+0x5d4/0x7c0

This is because in scatterwalk_copychunks(), we attempted to write to
a buffer (@sign) that was allocated in the stack (vmalloc area) by
crypt_message() and thus accessing its remaining 8 (x2) bytes ended up
crossing a page boundary.

To simply fix it, we could just pass @sign kmalloc'd from
crypt_message() and then we're done.  Luckily, we don't seem to pass
any other vmalloc'd buffers in smb_rqst::rq_iov...

Instead, let's map the correct pages and offsets from vmalloc buffers
as well in cifs_sg_set_buf() and then avoiding such oopses.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-14 10:16:25 +01:00
Anastasia Belova
5fc19c8313 cifs: add check for returning value of SMB2_set_info_init
[ Upstream commit a51e5d293dd1c2e7bf6f7be788466cd9b5d280fb ]

If the returning value of SMB2_set_info_init is an error-value,
exit the function.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 0967e54579 ("cifs: use a compound for setting an xattr")

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:45:48 +01:00
Zhang Xiaoxu
e13ef43813 cifs: Fix wrong return value checking when GETFLAGS
[ Upstream commit 92bbd67a55fee50743b42825d1c016e7fd5c79f9 ]

The return value of CIFSGetExtAttr is negative, should be checked
with -EOPNOTSUPP rather than EOPNOTSUPP.

Fixes: 64a5cfa6db ("Allow setting per-file compression via SMB2/3")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:45:48 +01:00
Anastasia Belova
3aeb13bc3d cifs: add check for returning value of SMB2_close_init
[ Upstream commit d520de6cb42e88a1d008b54f935caf9fc05951da ]

If the returning value of SMB2_close_init is an error-value,
exit the function.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 352d96f3ac ("cifs: multichannel: move channel selection above transport layer")

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25 17:45:47 +01:00
Zhang Xiaoxu
7286f87551 cifs: Fix xid leak in cifs_ses_add_channel()
[ Upstream commit e909d054bdea75ef1ec48c18c5936affdaecbb2c ]

Before return, should free the xid, otherwise, the
xid will be leaked.

Fixes: d70e9fa558 ("cifs: try opening channels after mounting")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:17 +01:00
Zhang Xiaoxu
2d08311aa3 cifs: Fix xid leak in cifs_flock()
[ Upstream commit 575e079c782b9862ec2626403922d041a42e6ed6 ]

If not flock, before return -ENOLCK, should free the xid,
otherwise, the xid will be leaked.

Fixes: d0677992d2 ("cifs: add support for flock")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:16 +01:00
Zhang Xiaoxu
bf49d4fe4a cifs: Fix xid leak in cifs_copy_file_range()
[ Upstream commit 9a97df404a402fe1174d2d1119f87ff2a0ca2fe9 ]

If the file is used by swap, before return -EOPNOTSUPP, should
free the xid, otherwise, the xid will be leaked.

Fixes: 4e8aea30f7 ("smb3: enable swap on SMB3 mounts")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:16 +01:00
Steve French
d11e09953c smb3: must initialize two ACL struct fields to zero
commit f09bd695af3b8ab46fc24e5d6954a24104c38387 upstream.

Coverity spotted that we were not initalizing Stbz1 and Stbz2 to
zero in create_sd_buf.

Addresses-Coverity: 1513848 ("Uninitialized scalar variable")
Cc: <stable@vger.kernel.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:17 +02:00
Zhang Xiaoxu
9312e04b6c cifs: Fix the error length of VALIDATE_NEGOTIATE_INFO message
commit e98ecc6e94f4e6d21c06660b0f336df02836694f upstream.

Commit d5c7076b77 ("smb3: add smb3.1.1 to default dialect list")
extend the dialects from 3 to 4, but forget to decrease the extended
length when specific the dialect, then the message length is larger
than expected.

This maybe leak some info through network because not initialize the
message body.

After apply this patch, the VALIDATE_NEGOTIATE_INFO message length is
reduced from 28 bytes to 26 bytes.

Fixes: d5c7076b77 ("smb3: add smb3.1.1 to default dialect list")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Cc: <stable@vger.kernel.org>
Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:07 +02:00
Ronnie Sahlberg
64f23e5430 cifs: destage dirty pages before re-reading them for cache=none
commit bb44c31cdcac107344dd2fcc3bd0504a53575c51 upstream.

This is the opposite case of kernel bugzilla 216301.
If we mmap a file using cache=none and then proceed to update the mmapped
area these updates are not reflected in a later pread() of that part of the
file.
To fix this we must first destage any dirty pages in the range before
we allow the pread() to proceed.

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:07 +02:00
Stefan Metzmacher
2a2e503a62 cifs: always initialize struct msghdr smb_msg completely
[ Upstream commit bedc8f76b3539ac4f952114b316bcc2251e808ce ]

So far we were just lucky because the uninitialized members
of struct msghdr are not used by default on a SOCK_STREAM tcp
socket.

But as new things like msg_ubuf and sg_from_iter where added
recently, we should play on the safe side and avoid potention
problems in future.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28 11:10:39 +02:00
David Howells
877231b0e6 cifs: use discard iterator to discard unneeded network data more efficiently
[ Upstream commit cf0604a686b11175d8beae60281c4ccc95aaa5c2 ]

The iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it, was added to allow a network
filesystem to discard any unwanted data sent by a server.
Convert cifs_discard_from_socket() to use this.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: bedc8f76b353 ("cifs: always initialize struct msghdr smb_msg completely")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-28 11:10:38 +02:00
Stefan Metzmacher
331eba80cb cifs: don't send down the destination address to sendmsg for a SOCK_STREAM
commit 17d3df38dc5f4cec9b0ac6eb79c1859b6e2693a4 upstream.

This is ignored anyway by the tcp layer.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Cc: stable@vger.kernel.org
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-23 14:16:58 +02:00
Ronnie Sahlberg
f3fbd08e7c cifs: revalidate mapping when doing direct writes
commit 7500a99281dfed2d4a84771c933bcb9e17af279b upstream.

Kernel bugzilla: 216301

When doing direct writes we need to also invalidate the mapping in case
we have a cached copy of the affected page(s) in memory or else
subsequent reads of the data might return the old/stale content
before we wrote an update to the server.

Cc: stable@vger.kernel.org
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-23 14:16:58 +02:00
David Howells
015c2ec053 smb3: missing inode locks in punch hole
[ Upstream commit ba0803050d610d5072666be727bca5e03e55b242 ]

smb3 fallocate punch hole was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.

Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:32:04 +02:00
Enzo Matsumiya
98127f140b cifs: remove useless parameter 'is_fsctl' from SMB2_ioctl()
[ Upstream commit 400d0ad63b190895e29f43bc75b1260111d3fd34 ]

SMB2_ioctl() is always called with is_fsctl = true, so doesn't make any
sense to have it at all.

Thus, always set SMB2_0_IOCTL_IS_FSCTL flag on the request.

Also, as per MS-SMB2 3.3.5.15 "Receiving an SMB2 IOCTL Request", servers
must fail the request if the request flags is zero anyway.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:32:04 +02:00
Steve French
52a408548a smb3: check xattr value length earlier
[ Upstream commit 5fa2cffba0b82336a2244d941322eb1627ff787b ]

Coverity complains about assigning a pointer based on
value length before checking that value length goes
beyond the end of the SMB.  Although this is even more
unlikely as value length is a single byte, and the
pointer is not dereferenced until laterm, it is clearer
to check the lengths first.

Addresses-Coverity: 1467704 ("Speculative execution data leak")
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:38:21 +02:00
Paulo Alcantara
471a413201 cifs: fix reconnect on smb3 mount types
commit c36ee7dab7749f7be21f7a72392744490b2a9a2b upstream.

cifs.ko defines two file system types: cifs & smb3, and
__cifs_get_super() was not including smb3 file system type when
looking up superblocks, therefore failing to reconnect tcons in
cifs_tree_connect().

Fix this by calling iterate_supers_type() on both file system types.

Link: https://lore.kernel.org/r/CAFrh3J9soC36+BVuwHB=g9z_KB5Og2+p2_W+BBoBOZveErz14w@mail.gmail.com
Cc: stable@vger.kernel.org
Tested-by: Satadru Pramanik <satadru@gmail.com>
Reported-by: Satadru Pramanik <satadru@gmail.com>
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:32:45 +02:00
Shyam Prasad N
9023ecfd33 cifs: return errors during session setup during reconnects
commit 8ea21823aa584b55ba4b861307093b78054b0c1b upstream.

During reconnects, we check the return value from
cifs_negotiate_protocol, and have handlers for both success
and failures. But if that passes, and cifs_setup_session
returns any errors other than -EACCES, we do not handle
that. This fix adds a handler for that, so that we don't
go ahead and try a tree_connect on a failed session.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:32:45 +02:00
Steve French
a262e1255b cifs: version operations for smb20 unneeded when legacy support disabled
[ Upstream commit 7ef93ffccd55fb0ba000ed16ef6a81cd7dee07b5 ]

We should not be including unused smb20 specific code when legacy
support is disabled (CONFIG_CIFS_ALLOW_INSECURE_LEGACY turned
off).  For example smb2_operations and smb2_values aren't used
in that case.  Over time we can move more and more SMB1/CIFS and SMB2.0
code into the insecure legacy ifdefs

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:44 +02:00
Steve French
6182c71a0c SMB3: EBADF/EIO errors in rename/open caused by race condition in smb2_compound_op
commit 0a55cf74ffb5d004b93647e4389096880ce37d6b upstream.

There is  a race condition in smb2_compound_op:

after_close:
	num_rqst++;

	if (cfile) {
		cifsFileInfo_put(cfile); // sends SMB2_CLOSE to the server
		cfile = NULL;

This is triggered by smb2_query_path_info operation that happens during
revalidate_dentry. In smb2_query_path_info, get_readable_path is called to
load the cfile, increasing the reference counter. If in the meantime, this
reference becomes the very last, this call to cifsFileInfo_put(cfile) will
trigger a SMB2_CLOSE request sent to the server just before sending this compound
request – and so then the compound request fails either with EBADF/EIO depending
on the timing at the server, because the handle is already closed.

In the first scenario, the race seems to be happening between smb2_query_path_info
triggered by the rename operation, and between “cleanup” of asynchronous writes – while
fsync(fd) likely waits for the asynchronous writes to complete, releasing the writeback
structures can happen after the close(fd) call. So the EBADF/EIO errors will pop up if
the timing is such that:
1) There are still outstanding references after close(fd) in the writeback structures
2) smb2_query_path_info successfully fetches the cfile, increasing the refcounter by 1
3) All writeback structures release the same cfile, reducing refcounter to 1
4) smb2_compound_op is called with that cfile

In the second scenario, the race seems to be similar – here open triggers the
smb2_query_path_info operation, and if all other threads in the meantime decrease the
refcounter to 1 similarly to the first scenario, again SMB2_CLOSE will be sent to the
server just before issuing the compound request. This case is harder to reproduce.

See https://bugzilla.samba.org/show_bug.cgi?id=15051

Cc: stable@vger.kernel.org
Fixes: 8de9e86c67 ("cifs: create a helper to find a writeable handle by path name")
Signed-off-by: Ondrej Hubsch <ohubsch@purestorage.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:21:28 +02:00
Ronnie Sahlberg
c9ac773715 cifs: when extending a file with falloc we should make files not-sparse
commit f66f8b94e7f2f4ac9fffe710be231ca8f25c5057 upstream.

as this is the only way to make sure the region is allocated.
Fix the conditional that was wrong and only tried to make already
non-sparse files non-sparse.

Cc: stable@vger.kernel.org
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:20:48 +02:00
Ronnie Sahlberg
5399e7b80c cifs: destage any unwritten data to the server before calling copychunk_write
[ Upstream commit f5d0f921ea362636e4a2efb7c38d1ead373a8700 ]

because the copychunk_write might cover a region of the file that has not yet
been sent to the server and thus fail.

A simple way to reproduce this is:
truncate -s 0 /mnt/testfile; strace -f -o x -ttT xfs_io -i -f -c 'pwrite 0k 128k' -c 'fcollapse 16k 24k' /mnt/testfile

the issue is that the 'pwrite 0k 128k' becomes rearranged on the wire with
the 'fcollapse 16k 24k' due to write-back caching.

fcollapse is implemented in cifs.ko as a SMB2 IOCTL(COPYCHUNK_WRITE) call
and it will fail serverside since the file is still 0b in size serverside
until the writes have been destaged.
To avoid this we must ensure that we destage any unwritten data to the
server before calling COPYCHUNK_WRITE.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1997373
Reported-by: Xiaoli Feng <xifeng@redhat.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-09 09:05:06 +02:00
David Howells
5bef9fc38f cifs: Check the IOCB_DIRECT flag, not O_DIRECT
[ Upstream commit 994fd530a512597ffcd713b0f6d5bc916c5698f0 ]

Use the IOCB_DIRECT indicator flag on the I/O context rather than checking to
see if the file was opened O_DIRECT.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-27 13:53:53 +02:00
Harshit Mogalapalli
4e166a4118 cifs: potential buffer overflow in handling symlinks
[ Upstream commit 64c4a37ac04eeb43c42d272f6e6c8c12bfcf4304 ]

Smatch printed a warning:
	arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error:
	__memcpy() 'dctx->buf' too small (16 vs u32max)

It's caused because Smatch marks 'link_len' as untrusted since it comes
from sscanf(). Add a check to ensure that 'link_len' is not larger than
the size of the 'link_str' buffer.

Fixes: c69c1b6eae ("cifs: implement CIFSParseMFSymlink()")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-20 09:23:18 +02:00
Paulo Alcantara
edefc4b2a8 cifs: fix NULL ptr dereference in smb2_ioctl_query_info()
commit d6f5e358452479fa8a773b5c6ccc9e4ec5a20880 upstream.

When calling smb2_ioctl_query_info() with invalid
smb_query_info::flags, a NULL ptr dereference is triggered when trying
to kfree() uninitialised rqst[n].rq_iov array.

This also fixes leaked paths that are created in SMB2_open_init()
which required SMB2_open_free() to properly free them.

Here is a small C reproducer that triggers it

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <sys/ioctl.h>

	#define die(s) perror(s), exit(1)
	#define QUERY_INFO 0xc018cf07

	int main(int argc, char *argv[])
	{
		int fd;

		if (argc < 2)
			exit(1);
		fd = open(argv[1], O_RDONLY);
		if (fd == -1)
			die("open");
		if (ioctl(fd, QUERY_INFO, (uint32_t[]) { 0, 0, 0, 4, 0, 0}) == -1)
			die("ioctl");
		close(fd);
		return 0;
	}

	mount.cifs //srv/share /mnt -o ...
	gcc repro.c && ./a.out /mnt/f0

	[ 1832.124468] CIFS: VFS: \\w22-dc.zelda.test\test Invalid passthru query flags: 0x4
	[ 1832.125043] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
	[ 1832.125764] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
	[ 1832.126241] CPU: 3 PID: 1133 Comm: a.out Not tainted 5.17.0-rc8 #2
	[ 1832.126630] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
	[ 1832.127322] RIP: 0010:smb2_ioctl_query_info+0x7a3/0xe30 [cifs]
	[ 1832.127749] Code: 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 6c 05 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 74 24 28 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 cb 04 00 00 49 8b 3e e8 bb fc fa ff 48 89 da 48
	[ 1832.128911] RSP: 0018:ffffc90000957b08 EFLAGS: 00010256
	[ 1832.129243] RAX: dffffc0000000000 RBX: ffff888117e9b850 RCX: ffffffffa020580d
	[ 1832.129691] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a2c0
	[ 1832.130137] RBP: ffff888117e9b878 R08: 0000000000000001 R09: 0000000000000003
	[ 1832.130585] R10: fffffbfff4087458 R11: 0000000000000001 R12: ffff888117e9b800
	[ 1832.131037] R13: 00000000ffffffea R14: 0000000000000000 R15: ffff888117e9b8a8
	[ 1832.131485] FS:  00007fcee9900740(0000) GS:ffff888151a00000(0000) knlGS:0000000000000000
	[ 1832.131993] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
	[ 1832.132354] CR2: 00007fcee9a1ef5e CR3: 0000000114cd2000 CR4: 0000000000350ee0
	[ 1832.132801] Call Trace:
	[ 1832.132962]  <TASK>
	[ 1832.133104]  ? smb2_query_reparse_tag+0x890/0x890 [cifs]
	[ 1832.133489]  ? cifs_mapchar+0x460/0x460 [cifs]
	[ 1832.133822]  ? rcu_read_lock_sched_held+0x3f/0x70
	[ 1832.134125]  ? cifs_strndup_to_utf16+0x15b/0x250 [cifs]
	[ 1832.134502]  ? lock_downgrade+0x6f0/0x6f0
	[ 1832.134760]  ? cifs_convert_path_to_utf16+0x198/0x220 [cifs]
	[ 1832.135170]  ? smb2_check_message+0x1080/0x1080 [cifs]
	[ 1832.135545]  cifs_ioctl+0x1577/0x3320 [cifs]
	[ 1832.135864]  ? lock_downgrade+0x6f0/0x6f0
	[ 1832.136125]  ? cifs_readdir+0x2e60/0x2e60 [cifs]
	[ 1832.136468]  ? rcu_read_lock_sched_held+0x3f/0x70
	[ 1832.136769]  ? __rseq_handle_notify_resume+0x80b/0xbe0
	[ 1832.137096]  ? __up_read+0x192/0x710
	[ 1832.137327]  ? __ia32_sys_rseq+0xf0/0xf0
	[ 1832.137578]  ? __x64_sys_openat+0x11f/0x1d0
	[ 1832.137850]  __x64_sys_ioctl+0x127/0x190
	[ 1832.138103]  do_syscall_64+0x3b/0x90
	[ 1832.138378]  entry_SYSCALL_64_after_hwframe+0x44/0xae
	[ 1832.138702] RIP: 0033:0x7fcee9a253df
	[ 1832.138937] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00
	[ 1832.140107] RSP: 002b:00007ffeba94a8a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
	[ 1832.140606] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcee9a253df
	[ 1832.141058] RDX: 00007ffeba94a910 RSI: 00000000c018cf07 RDI: 0000000000000003
	[ 1832.141503] RBP: 00007ffeba94a930 R08: 00007fcee9b24db0 R09: 00007fcee9b45c4e
	[ 1832.141948] R10: 00007fcee9918d40 R11: 0000000000000246 R12: 00007ffeba94aa48
	[ 1832.142396] R13: 0000000000401176 R14: 0000000000403df8 R15: 00007fcee9b78000
	[ 1832.142851]  </TASK>
	[ 1832.142994] Modules linked in: cifs cifs_arc4 cifs_md4 bpf_preload [last unloaded: cifs]

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:39:53 +02:00
Paulo Alcantara
9963ccea60 cifs: prevent bad output lengths in smb2_ioctl_query_info()
commit b92e358757b91c2827af112cae9af513f26a3f34 upstream.

When calling smb2_ioctl_query_info() with
smb_query_info::flags=PASSTHRU_FSCTL and
smb_query_info::output_buffer_length=0, the following would return
0x10

	buffer = memdup_user(arg + sizeof(struct smb_query_info),
			     qi.output_buffer_length);
	if (IS_ERR(buffer)) {
		kfree(vars);
		return PTR_ERR(buffer);
	}

rather than a valid pointer thus making IS_ERR() check fail.  This
would then cause a NULL ptr deference in @buffer when accessing it
later in smb2_ioctl_query_ioctl().  While at it, prevent having a
@buffer smaller than 8 bytes to correctly handle SMB2_SET_INFO
FileEndOfFileInformation requests when
smb_query_info::flags=PASSTHRU_SET_INFO.

Here is a small C reproducer which triggers a NULL ptr in @buffer when
passing an invalid smb_query_info::flags

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <unistd.h>
	#include <fcntl.h>
	#include <sys/ioctl.h>

	#define die(s) perror(s), exit(1)
	#define QUERY_INFO 0xc018cf07

	int main(int argc, char *argv[])
	{
		int fd;

		if (argc < 2)
			exit(1);
		fd = open(argv[1], O_RDONLY);
		if (fd == -1)
			die("open");
		if (ioctl(fd, QUERY_INFO, (uint32_t[]) { 0, 0, 0, 4, 0, 0}) == -1)
			die("ioctl");
		close(fd);
		return 0;
	}

	mount.cifs //srv/share /mnt -o ...
	gcc repro.c && ./a.out /mnt/f0

	[  114.138620] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
	[  114.139310] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
	[  114.139775] CPU: 2 PID: 995 Comm: a.out Not tainted 5.17.0-rc8 #1
	[  114.140148] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
	[  114.140818] RIP: 0010:smb2_ioctl_query_info+0x206/0x410 [cifs]
	[  114.141221] Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 28 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9c 01 00 00 49 8b 3f e8 58 02 fb ff 48 8b 14 24
	[  114.142348] RSP: 0018:ffffc90000b47b00 EFLAGS: 00010256
	[  114.142692] RAX: dffffc0000000000 RBX: ffff888115503200 RCX: ffffffffa020580d
	[  114.143119] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a380
	[  114.143544] RBP: ffff888115503278 R08: 0000000000000001 R09: 0000000000000003
	[  114.143983] R10: fffffbfff4087470 R11: 0000000000000001 R12: ffff888115503288
	[  114.144424] R13: 00000000ffffffea R14: ffff888115503228 R15: 0000000000000000
	[  114.144852] FS:  00007f7aeabdf740(0000) GS:ffff888151600000(0000) knlGS:0000000000000000
	[  114.145338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
	[  114.145692] CR2: 00007f7aeacfdf5e CR3: 000000012000e000 CR4: 0000000000350ee0
	[  114.146131] Call Trace:
	[  114.146291]  <TASK>
	[  114.146432]  ? smb2_query_reparse_tag+0x890/0x890 [cifs]
	[  114.146800]  ? cifs_mapchar+0x460/0x460 [cifs]
	[  114.147121]  ? rcu_read_lock_sched_held+0x3f/0x70
	[  114.147412]  ? cifs_strndup_to_utf16+0x15b/0x250 [cifs]
	[  114.147775]  ? dentry_path_raw+0xa6/0xf0
	[  114.148024]  ? cifs_convert_path_to_utf16+0x198/0x220 [cifs]
	[  114.148413]  ? smb2_check_message+0x1080/0x1080 [cifs]
	[  114.148766]  ? rcu_read_lock_sched_held+0x3f/0x70
	[  114.149065]  cifs_ioctl+0x1577/0x3320 [cifs]
	[  114.149371]  ? lock_downgrade+0x6f0/0x6f0
	[  114.149631]  ? cifs_readdir+0x2e60/0x2e60 [cifs]
	[  114.149956]  ? rcu_read_lock_sched_held+0x3f/0x70
	[  114.150250]  ? __rseq_handle_notify_resume+0x80b/0xbe0
	[  114.150562]  ? __up_read+0x192/0x710
	[  114.150791]  ? __ia32_sys_rseq+0xf0/0xf0
	[  114.151025]  ? __x64_sys_openat+0x11f/0x1d0
	[  114.151296]  __x64_sys_ioctl+0x127/0x190
	[  114.151549]  do_syscall_64+0x3b/0x90
	[  114.151768]  entry_SYSCALL_64_after_hwframe+0x44/0xae
	[  114.152079] RIP: 0033:0x7f7aead043df
	[  114.152306] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00
	[  114.153431] RSP: 002b:00007ffc2e0c1f80 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
	[  114.153890] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7aead043df
	[  114.154315] RDX: 00007ffc2e0c1ff0 RSI: 00000000c018cf07 RDI: 0000000000000003
	[  114.154747] RBP: 00007ffc2e0c2010 R08: 00007f7aeae03db0 R09: 00007f7aeae24c4e
	[  114.155192] R10: 00007f7aeabf7d40 R11: 0000000000000246 R12: 00007ffc2e0c2128
	[  114.155642] R13: 0000000000401176 R14: 0000000000403df8 R15: 00007f7aeae57000
	[  114.156071]  </TASK>
	[  114.156218] Modules linked in: cifs cifs_arc4 cifs_md4 bpf_preload
	[  114.156608] ---[ end trace 0000000000000000 ]---
	[  114.156898] RIP: 0010:smb2_ioctl_query_info+0x206/0x410 [cifs]
	[  114.157792] Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 28 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9c 01 00 00 49 8b 3f e8 58 02 fb ff 48 8b 14 24
	[  114.159293] RSP: 0018:ffffc90000b47b00 EFLAGS: 00010256
	[  114.159641] RAX: dffffc0000000000 RBX: ffff888115503200 RCX: ffffffffa020580d
	[  114.160093] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a380
	[  114.160699] RBP: ffff888115503278 R08: 0000000000000001 R09: 0000000000000003
	[  114.161196] R10: fffffbfff4087470 R11: 0000000000000001 R12: ffff888115503288
	[  114.155642] R13: 0000000000401176 R14: 0000000000403df8 R15: 00007f7aeae57000
	[  114.156071]  </TASK>
	[  114.156218] Modules linked in: cifs cifs_arc4 cifs_md4 bpf_preload
	[  114.156608] ---[ end trace 0000000000000000 ]---
	[  114.156898] RIP: 0010:smb2_ioctl_query_info+0x206/0x410 [cifs]
	[  114.157792] Code: 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 c8 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 28 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9c 01 00 00 49 8b 3f e8 58 02 fb ff 48 8b 14 24
	[  114.159293] RSP: 0018:ffffc90000b47b00 EFLAGS: 00010256
	[  114.159641] RAX: dffffc0000000000 RBX: ffff888115503200 RCX: ffffffffa020580d
	[  114.160093] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffffa043a380
	[  114.160699] RBP: ffff888115503278 R08: 0000000000000001 R09: 0000000000000003
	[  114.161196] R10: fffffbfff4087470 R11: 0000000000000001 R12: ffff888115503288
	[  114.161823] R13: 00000000ffffffea R14: ffff888115503228 R15: 0000000000000000
	[  114.162274] FS:  00007f7aeabdf740(0000) GS:ffff888151600000(0000) knlGS:0000000000000000
	[  114.162853] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
	[  114.163218] CR2: 00007f7aeacfdf5e CR3: 000000012000e000 CR4: 0000000000350ee0
	[  114.163691] Kernel panic - not syncing: Fatal exception
	[  114.164087] Kernel Offset: disabled
	[  114.164316] ---[ end Kernel panic - not syncing: Fatal exception ]---

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:39:53 +02:00
Ronnie Sahlberg
df9db1a2af cifs: fix double free race when mount fails in cifs_get_root()
[ Upstream commit 3d6cc9898efdfb062efb74dc18cfc700e082f5d5 ]

When cifs_get_root() fails during cifs_smb3_do_mount() we call
deactivate_locked_super() which eventually will call delayed_free() which
will free the context.
In this situation we should not proceed to enter the out: section in
cifs_smb3_do_mount() and free the same resources a second time.

[Thu Feb 10 12:59:06 2022] BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022] Read of size 8 at addr ffff888364f4d110 by task swapper/1/0

[Thu Feb 10 12:59:06 2022] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G           OE     5.17.0-rc3+ #4
[Thu Feb 10 12:59:06 2022] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019
[Thu Feb 10 12:59:06 2022] Call Trace:
[Thu Feb 10 12:59:06 2022]  <IRQ>
[Thu Feb 10 12:59:06 2022]  dump_stack_lvl+0x5d/0x78
[Thu Feb 10 12:59:06 2022]  print_address_description.constprop.0+0x24/0x150
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  kasan_report.cold+0x7d/0x117
[Thu Feb 10 12:59:06 2022]  ? rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  __asan_load8+0x86/0xa0
[Thu Feb 10 12:59:06 2022]  rcu_cblist_dequeue+0x32/0x60
[Thu Feb 10 12:59:06 2022]  rcu_core+0x547/0xca0
[Thu Feb 10 12:59:06 2022]  ? call_rcu+0x3c0/0x3c0
[Thu Feb 10 12:59:06 2022]  ? __this_cpu_preempt_check+0x13/0x20
[Thu Feb 10 12:59:06 2022]  ? lock_is_held_type+0xea/0x140
[Thu Feb 10 12:59:06 2022]  rcu_core_si+0xe/0x10
[Thu Feb 10 12:59:06 2022]  __do_softirq+0x1d4/0x67b
[Thu Feb 10 12:59:06 2022]  __irq_exit_rcu+0x100/0x150
[Thu Feb 10 12:59:06 2022]  irq_exit_rcu+0xe/0x30
[Thu Feb 10 12:59:06 2022]  sysvec_hyperv_stimer0+0x9d/0xc0
...
[Thu Feb 10 12:59:07 2022] Freed by task 58179:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  kasan_set_track+0x25/0x30
[Thu Feb 10 12:59:07 2022]  kasan_set_free_info+0x24/0x40
[Thu Feb 10 12:59:07 2022]  ____kasan_slab_free+0x137/0x170
[Thu Feb 10 12:59:07 2022]  __kasan_slab_free+0x12/0x20
[Thu Feb 10 12:59:07 2022]  slab_free_freelist_hook+0xb3/0x1d0
[Thu Feb 10 12:59:07 2022]  kfree+0xcd/0x520
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0x149/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

[Thu Feb 10 12:59:07 2022] Last potentially related work creation:
[Thu Feb 10 12:59:07 2022]  kasan_save_stack+0x26/0x50
[Thu Feb 10 12:59:07 2022]  __kasan_record_aux_stack+0xb6/0xc0
[Thu Feb 10 12:59:07 2022]  kasan_record_aux_stack_noalloc+0xb/0x10
[Thu Feb 10 12:59:07 2022]  call_rcu+0x76/0x3c0
[Thu Feb 10 12:59:07 2022]  cifs_umount+0xce/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  cifs_kill_sb+0xc8/0xe0 [cifs]
[Thu Feb 10 12:59:07 2022]  deactivate_locked_super+0x5d/0xd0
[Thu Feb 10 12:59:07 2022]  cifs_smb3_do_mount+0xab9/0xbe0 [cifs]
[Thu Feb 10 12:59:07 2022]  smb3_get_tree+0x1a0/0x2e0 [cifs]
[Thu Feb 10 12:59:07 2022]  vfs_get_tree+0x52/0x140
[Thu Feb 10 12:59:07 2022]  path_mount+0x635/0x10c0
[Thu Feb 10 12:59:07 2022]  __x64_sys_mount+0x1bf/0x210
[Thu Feb 10 12:59:07 2022]  do_syscall_64+0x5c/0xc0
[Thu Feb 10 12:59:07 2022]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:09:29 +01:00
Steve French
5655b8bccb smb3: do not error on fsync when readonly
[ Upstream commit 71e6864eacbef0b2645ca043cdfbac272cb6cea3 ]

Linux allows doing a flush/fsync on a file open for read-only,
but the protocol does not allow that.  If the file passed in
on the flush is read-only try to find a writeable handle for
the same inode, if that is not possible skip sending the
fsync call to the server to avoid breaking the apps.

Reported-by: Julian Sikorski <belegdol@gmail.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Suggested-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01 09:19:08 +01:00
Steve French
84778fd66d smb3: correct smb3 ACL security descriptor
[ Upstream commit b06d893ef2492245d0319b4136edb4c346b687a3 ]

Address warning:

        fs/smbfs_client/smb2pdu.c:2425 create_sd_buf()
        warn: struct type mismatch 'smb3_acl vs cifs_acl'

Pointed out by Dan Carpenter via smatch code analysis tool

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-09 14:40:57 +02:00
Dan Carpenter
3d42ed6b79 cifs: fix a sign extension bug
[ Upstream commit e946d3c887a9dc33aa82a349c6284f4a084163f4 ]

The problem is the mismatched types between "ctx->total_len" which is
an unsigned int, "rc" which is an int, and "ctx->rc" which is a
ssize_t.  The code does:

	ctx->rc = (rc == 0) ? ctx->total_len : rc;

We want "ctx->rc" to store the negative "rc" error code.  But what
happens is that "rc" is type promoted to a high unsigned int and
'ctx->rc" will store the high positive value instead of a negative
value.

The fix is to change "rc" from an int to a ssize_t.

Fixes: c610c4b619 ("CIFS: Add asynchronous write support through kernel AIO")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:11:04 +02:00
Steve French
93028da5e9 cifs: fix incorrect check for null pointer in header_assemble
commit 9ed38fd4a15417cac83967360cf20b853bfab9b6 upstream.

Although very unlikely that the tlink pointer would be null in this case,
get_next_mid function can in theory return null (but not an error)
so need to check for null (not for IS_ERR, which can not be returned
here).

Address warning:

        fs/smbfs_client/connect.c:2392 cifs_match_super()
        warn: 'tlink' isn't an ERR_PTR

Pointed out by Dan Carpenter via smatch code analysis tool

CC: stable@vger.kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-30 10:10:59 +02:00
Ding Hui
ba2faddf1f cifs: fix wrong release in sess_alloc_buffer() failed path
[ Upstream commit d72c74197b70bc3c95152f351a568007bffa3e11 ]

smb_buf is allocated by small_smb_init_no_tc(), and buf type is
CIFS_SMALL_BUFFER, so we should use cifs_small_buf_release() to
release it in failed path.

Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18 13:40:32 +02:00
Len Baker
6c4857203f CIFS: Fix a potencially linear read overflow
[ Upstream commit f980d055a0f858d73d9467bb0b570721bbfcdfb8 ]

strlcpy() reads the entire source buffer first. This read may exceed the
destination size limit. This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated.

Also, the strnlen() call does not avoid the read overflow in the strlcpy
function when a not NUL-terminated string is passed.

So, replace this block by a call to kstrndup() that avoids this type of
overflow and does the same.

Fixes: 066ce68994 ("cifs: rename cifs_strlcpy_to_host and make it use new functions")
Signed-off-by: Len Baker <len.baker@gmx.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15 09:50:43 +02:00