linux.git/fs/cifs, branch v6.1 Linux kernel source tree cifs: fix missing unlock in cifs_file_copychunk_range() 2022-11-21T16:27:03+00:00 ChenXiaoSong chenxiaosong2@huawei.com 2022-11-19T04:51:59+00:00 502487847743018c93d75b401eac2ea4c4973123 xfstests generic/013 and generic/476 reported WARNING as follows: WARNING: lock held when returning to user space! 6.1.0-rc5+ #4 Not tainted ------------------------------------------------ fsstress/504233 is leaving the kernel with locks still held! 2 locks held by fsstress/504233: #0: ffff888054c38850 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: lock_two_nondirectories+0xcf/0xf0 #1: ffff8880b8fec750 (&sb->s_type->i_mutex_key#21/4){+.+.}-{3:3}, at: lock_two_nondirectories+0xb7/0xf0 This will lead to deadlock and hungtask. Fix this by releasing locks when failed to write out on a file range in cifs_file_copychunk_range(). Fixes: 3e3761f1ec7d ("smb3: use filemap_write_and_wait_range instead of filemap_write_and_wait") Cc: stable@vger.kernel.org # 6.0 Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> 
xfstests generic/013 and generic/476 reported WARNING as follows:

  WARNING: lock held when returning to user space!
  6.1.0-rc5+ #4 Not tainted
  ------------------------------------------------
  fsstress/504233 is leaving the kernel with locks still held!
  2 locks held by fsstress/504233:
   #0: ffff888054c38850 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at:
                        lock_two_nondirectories+0xcf/0xf0
   #1: ffff8880b8fec750 (&sb->s_type->i_mutex_key#21/4){+.+.}-{3:3}, at:
                        lock_two_nondirectories+0xb7/0xf0

This will lead to deadlock and hungtask.

Fix this by releasing locks when failed to write out on a file range in
cifs_file_copychunk_range().

Fixes: 3e3761f1ec7d ("smb3: use filemap_write_and_wait_range instead of filemap_write_and_wait")
Cc: stable@vger.kernel.org # 6.0
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: Use after free in debug code 2022-11-19T20:27:37+00:00 Dan Carpenter dan.carpenter@oracle.com 2022-11-18T11:48:00+00:00 f391d6ee002ea022c62dc0b09d0578f3ccce81be This debug code dereferences "old_iface" after it was already freed by the call to release_iface(). Re-order the debugging to avoid this issue. Fixes: b54034a73baf ("cifs: during reconnect, update interface if necessary") Cc: stable@vger.kernel.org # 5.19+ Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steve French <stfrench@microsoft.com> 
This debug code dereferences "old_iface" after it was already freed by
the call to release_iface().  Re-order the debugging to avoid this
issue.

Fixes: b54034a73baf ("cifs: during reconnect, update interface if necessary")
Cc: stable@vger.kernel.org # 5.19+
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: add check for returning value of SMB2_set_info_init 2022-11-16T18:24:26+00:00 Anastasia Belova abelova@astralinux.ru 2022-11-16T14:10:27+00:00 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: 0967e5457954 ("cifs: use a compound for setting an xattr") Signed-off-by: Anastasia Belova <abelova@astralinux.ru> Signed-off-by: Steve French <stfrench@microsoft.com> 
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: 0967e5457954 ("cifs: use a compound for setting an xattr")

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: Fix wrong return value checking when GETFLAGS 2022-11-16T06:21:04+00:00 Zhang Xiaoxu zhangxiaoxu5@huawei.com 2022-11-15T10:39:34+00:00 92bbd67a55fee50743b42825d1c016e7fd5c79f9 The return value of CIFSGetExtAttr is negative, should be checked with -EOPNOTSUPP rather than EOPNOTSUPP. Fixes: 64a5cfa6db94 ("Allow setting per-file compression via SMB2/3") Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> 
The return value of CIFSGetExtAttr is negative, should be checked
with -EOPNOTSUPP rather than EOPNOTSUPP.

Fixes: 64a5cfa6db94 ("Allow setting per-file compression via SMB2/3")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: add check for returning value of SMB2_close_init 2022-11-15T18:57:54+00:00 Anastasia Belova abelova@astralinux.ru 2022-11-15T14:27:01+00:00 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: 352d96f3acc6 ("cifs: multichannel: move channel selection above transport layer") Signed-off-by: Anastasia Belova <abelova@astralinux.ru> Signed-off-by: Steve French <stfrench@microsoft.com> 
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: 352d96f3acc6 ("cifs: multichannel: move channel selection above transport layer")

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: Fix connections leak when tlink setup failed 2022-11-11T17:59:30+00:00 Zhang Xiaoxu zhangxiaoxu5@huawei.com 2022-11-11T07:12:12+00:00 1dcdf5f5b2137185cbdd5385f29949ab3da4f00c If the tlink setup failed, lost to put the connections, then the module refcnt leak since the cifsd kthread not exit. Also leak the fscache info, and for next mount with fsc, it will print the follow errors: CIFS: Cache volume key already in use (cifs,127.0.0.1:445,TEST) Let's check the result of tlink setup, and do some cleanup. Fixes: 56c762eb9bee ("cifs: Refactor out cifs_mount()") Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com> 
If the tlink setup failed, lost to put the connections, then
the module refcnt leak since the cifsd kthread not exit.

Also leak the fscache info, and for next mount with fsc, it will
print the follow errors:
  CIFS: Cache volume key already in use (cifs,127.0.0.1:445,TEST)

Let's check the result of tlink setup, and do some cleanup.

Fixes: 56c762eb9bee ("cifs: Refactor out cifs_mount()")
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: fix use-after-free on the link name 2022-11-05T04:36:54+00:00 ChenXiaoSong chenxiaosong2@huawei.com 2022-11-04T07:44:41+00:00 542228db2f28fdf775b301f2843e1fe486e7c797 xfstests generic/011 reported use-after-free bug as follows: BUG: KASAN: use-after-free in __d_alloc+0x269/0x859 Read of size 15 at addr ffff8880078933a0 by task dirstress/952 CPU: 1 PID: 952 Comm: dirstress Not tainted 6.1.0-rc3+ #77 Call Trace: __dump_stack+0x23/0x29 dump_stack_lvl+0x51/0x73 print_address_description+0x67/0x27f print_report+0x3e/0x5c kasan_report+0x7b/0xa8 kasan_check_range+0x1b2/0x1c1 memcpy+0x22/0x5d __d_alloc+0x269/0x859 d_alloc+0x45/0x20c d_alloc_parallel+0xb2/0x8b2 lookup_open+0x3b8/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Allocated by task 952: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_alloc_info+0x17/0x1d __kasan_kmalloc+0x7e/0x87 __kmalloc_node_track_caller+0x59/0x155 kstrndup+0x60/0xe6 parse_mf_symlink+0x215/0x30b check_mf_symlink+0x260/0x36a cifs_get_inode_info+0x14e1/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 950: kasan_save_stack+0x1f/0x42 kasan_set_track+0x21/0x2a kasan_save_free_info+0x1c/0x34 ____kasan_slab_free+0x1c1/0x1d5 __kasan_slab_free+0xe/0x13 __kmem_cache_free+0x29a/0x387 kfree+0xd3/0x10e cifs_fattr_to_inode+0xb6a/0xc8c cifs_get_inode_info+0x3cb/0x1690 cifs_revalidate_dentry_attr+0x70d/0x964 cifs_revalidate_dentry+0x36/0x62 cifs_d_revalidate+0x162/0x446 lookup_open+0x36f/0x9f9 open_last_lookups+0x63d/0xc26 path_openat+0x11a/0x261 do_filp_open+0xcc/0x168 do_sys_openat2+0x13b/0x3f7 do_sys_open+0x10f/0x146 __se_sys_creat+0x27/0x2e __x64_sys_creat+0x55/0x6a do_syscall_64+0x40/0x96 entry_SYSCALL_64_after_hwframe+0x63/0xcd When opened a symlink, link name is from 'inode->i_link', but it may be reset to a new value when revalidate the dentry. If some processes get the link name on the race scenario, then UAF will happen on link name. Fix this by implementing 'get_link' interface to duplicate the link name. Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+") Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> 
xfstests generic/011 reported use-after-free bug as follows:

  BUG: KASAN: use-after-free in __d_alloc+0x269/0x859
  Read of size 15 at addr ffff8880078933a0 by task dirstress/952

  CPU: 1 PID: 952 Comm: dirstress Not tainted 6.1.0-rc3+ #77
  Call Trace:
   __dump_stack+0x23/0x29
   dump_stack_lvl+0x51/0x73
   print_address_description+0x67/0x27f
   print_report+0x3e/0x5c
   kasan_report+0x7b/0xa8
   kasan_check_range+0x1b2/0x1c1
   memcpy+0x22/0x5d
   __d_alloc+0x269/0x859
   d_alloc+0x45/0x20c
   d_alloc_parallel+0xb2/0x8b2
   lookup_open+0x3b8/0x9f9
   open_last_lookups+0x63d/0xc26
   path_openat+0x11a/0x261
   do_filp_open+0xcc/0x168
   do_sys_openat2+0x13b/0x3f7
   do_sys_open+0x10f/0x146
   __se_sys_creat+0x27/0x2e
   __x64_sys_creat+0x55/0x6a
   do_syscall_64+0x40/0x96
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

  Allocated by task 952:
   kasan_save_stack+0x1f/0x42
   kasan_set_track+0x21/0x2a
   kasan_save_alloc_info+0x17/0x1d
   __kasan_kmalloc+0x7e/0x87
   __kmalloc_node_track_caller+0x59/0x155
   kstrndup+0x60/0xe6
   parse_mf_symlink+0x215/0x30b
   check_mf_symlink+0x260/0x36a
   cifs_get_inode_info+0x14e1/0x1690
   cifs_revalidate_dentry_attr+0x70d/0x964
   cifs_revalidate_dentry+0x36/0x62
   cifs_d_revalidate+0x162/0x446
   lookup_open+0x36f/0x9f9
   open_last_lookups+0x63d/0xc26
   path_openat+0x11a/0x261
   do_filp_open+0xcc/0x168
   do_sys_openat2+0x13b/0x3f7
   do_sys_open+0x10f/0x146
   __se_sys_creat+0x27/0x2e
   __x64_sys_creat+0x55/0x6a
   do_syscall_64+0x40/0x96
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

  Freed by task 950:
   kasan_save_stack+0x1f/0x42
   kasan_set_track+0x21/0x2a
   kasan_save_free_info+0x1c/0x34
   ____kasan_slab_free+0x1c1/0x1d5
   __kasan_slab_free+0xe/0x13
   __kmem_cache_free+0x29a/0x387
   kfree+0xd3/0x10e
   cifs_fattr_to_inode+0xb6a/0xc8c
   cifs_get_inode_info+0x3cb/0x1690
   cifs_revalidate_dentry_attr+0x70d/0x964
   cifs_revalidate_dentry+0x36/0x62
   cifs_d_revalidate+0x162/0x446
   lookup_open+0x36f/0x9f9
   open_last_lookups+0x63d/0xc26
   path_openat+0x11a/0x261
   do_filp_open+0xcc/0x168
   do_sys_openat2+0x13b/0x3f7
   do_sys_open+0x10f/0x146
   __se_sys_creat+0x27/0x2e
   __x64_sys_creat+0x55/0x6a
   do_syscall_64+0x40/0x96
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

When opened a symlink, link name is from 'inode->i_link', but it may be
reset to a new value when revalidate the dentry. If some processes get the
link name on the race scenario, then UAF will happen on link name.

Fix this by implementing 'get_link' interface to duplicate the link name.

Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: avoid unnecessary iteration of tcp sessions 2022-11-05T04:34:40+00:00 Shyam Prasad N sprasad@microsoft.com 2022-10-28T10:01:45+00:00 23d9b9b757e8007204d8f71448ab55d5ef2ae8e5 In a few places, we do unnecessary iterations of tcp sessions, even when the server struct is provided. The change avoids it and uses the server struct provided. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> 
In a few places, we do unnecessary iterations of
tcp sessions, even when the server struct is provided.

The change avoids it and uses the server struct provided.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: always iterate smb sessions using primary channel 2022-11-05T04:34:02+00:00 Shyam Prasad N sprasad@microsoft.com 2022-10-28T09:52:26+00:00 8abcaeaed38109e5ccaf40218e0e9e387f07bfe6 smb sessions and tcons currently hang off primary channel only. Secondary channels have the lists as empty. Whenever there's a need to iterate sessions or tcons, we should use the list in the corresponding primary channel. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> 
smb sessions and tcons currently hang off primary channel only.
Secondary channels have the lists as empty. Whenever there's a
need to iterate sessions or tcons, we should use the list in the
corresponding primary channel.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
cifs: fix use-after-free caused by invalid pointer `hostname` 2022-10-28T04:59:13+00:00 Zeng Heng zengheng4@huawei.com 2022-10-27T12:45:28+00:00 153695d36ead0ccc4d0256953c751cabf673e621 `hostname` needs to be set as null-pointer after free in `cifs_put_tcp_session` function, or when `cifsd` thread attempts to resolve hostname and reconnect the host, the thread would deref the invalid pointer. Here is one of practical backtrace examples as reference: Task 477 --------------------------- do_mount path_mount do_new_mount vfs_get_tree smb3_get_tree smb3_get_tree_common cifs_smb3_do_mount cifs_mount mount_put_conns cifs_put_tcp_session --> kfree(server->hostname) cifsd --------------------------- kthread cifs_demultiplex_thread cifs_reconnect reconn_set_ipaddr_from_hostname --> if (!server->hostname) --> if (server->hostname[0] == '\0') // !! UAF fault here CIFS: VFS: cifs_mount failed w/return code = -112 mount error(112): Host is down BUG: KASAN: use-after-free in reconn_set_ipaddr_from_hostname+0x2ba/0x310 Read of size 1 at addr ffff888108f35380 by task cifsd/480 CPU: 2 PID: 480 Comm: cifsd Not tainted 6.1.0-rc2-00106-gf705792f89dd-dirty #25 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x68/0x85 print_report+0x16c/0x4a3 kasan_report+0x95/0x190 reconn_set_ipaddr_from_hostname+0x2ba/0x310 __cifs_reconnect.part.0+0x241/0x800 cifs_reconnect+0x65f/0xb60 cifs_demultiplex_thread+0x1570/0x2570 kthread+0x2c5/0x380 ret_from_fork+0x22/0x30 </TASK> Allocated by task 477: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x7e/0x90 __kmalloc_node_track_caller+0x52/0x1b0 kstrdup+0x3b/0x70 cifs_get_tcp_session+0xbc/0x19b0 mount_get_conns+0xa9/0x10c0 cifs_mount+0xdf/0x1970 cifs_smb3_do_mount+0x295/0x1660 smb3_get_tree+0x352/0x5e0 vfs_get_tree+0x8e/0x2e0 path_mount+0xf8c/0x1990 do_mount+0xee/0x110 __x64_sys_mount+0x14b/0x1f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 477: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x50 __kasan_slab_free+0x10a/0x190 __kmem_cache_free+0xca/0x3f0 cifs_put_tcp_session+0x30c/0x450 cifs_mount+0xf95/0x1970 cifs_smb3_do_mount+0x295/0x1660 smb3_get_tree+0x352/0x5e0 vfs_get_tree+0x8e/0x2e0 path_mount+0xf8c/0x1990 do_mount+0xee/0x110 __x64_sys_mount+0x14b/0x1f0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888108f35380 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff888108f35380, ffff888108f35390) The buggy address belongs to the physical page: page:00000000333f8e58 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888108f350e0 pfn:0x108f35 flags: 0x200000000000200(slab|node=0|zone=2) raw: 0200000000000200 0000000000000000 dead000000000122 ffff8881000423c0 raw: ffff888108f350e0 000000008080007a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888108f35280: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ffff888108f35300: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc >ffff888108f35380: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ^ ffff888108f35400: fa fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888108f35480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Fixes: 7be3248f3139 ("cifs: To match file servers, make sure the server hostname matches") Signed-off-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com> 
`hostname` needs to be set as null-pointer after free in
`cifs_put_tcp_session` function, or when `cifsd` thread attempts
to resolve hostname and reconnect the host, the thread would deref
the invalid pointer.

Here is one of practical backtrace examples as reference:

Task 477
---------------------------
 do_mount
  path_mount
   do_new_mount
    vfs_get_tree
     smb3_get_tree
      smb3_get_tree_common
       cifs_smb3_do_mount
        cifs_mount
         mount_put_conns
          cifs_put_tcp_session
          --> kfree(server->hostname)

cifsd
---------------------------
 kthread
  cifs_demultiplex_thread
   cifs_reconnect
    reconn_set_ipaddr_from_hostname
    --> if (!server->hostname)
    --> if (server->hostname[0] == '\0')  // !! UAF fault here

CIFS: VFS: cifs_mount failed w/return code = -112
mount error(112): Host is down
BUG: KASAN: use-after-free in reconn_set_ipaddr_from_hostname+0x2ba/0x310
Read of size 1 at addr ffff888108f35380 by task cifsd/480
CPU: 2 PID: 480 Comm: cifsd Not tainted 6.1.0-rc2-00106-gf705792f89dd-dirty #25
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x68/0x85
 print_report+0x16c/0x4a3
 kasan_report+0x95/0x190
 reconn_set_ipaddr_from_hostname+0x2ba/0x310
 __cifs_reconnect.part.0+0x241/0x800
 cifs_reconnect+0x65f/0xb60
 cifs_demultiplex_thread+0x1570/0x2570
 kthread+0x2c5/0x380
 ret_from_fork+0x22/0x30
 </TASK>
Allocated by task 477:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x7e/0x90
 __kmalloc_node_track_caller+0x52/0x1b0
 kstrdup+0x3b/0x70
 cifs_get_tcp_session+0xbc/0x19b0
 mount_get_conns+0xa9/0x10c0
 cifs_mount+0xdf/0x1970
 cifs_smb3_do_mount+0x295/0x1660
 smb3_get_tree+0x352/0x5e0
 vfs_get_tree+0x8e/0x2e0
 path_mount+0xf8c/0x1990
 do_mount+0xee/0x110
 __x64_sys_mount+0x14b/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 477:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x2a/0x50
 __kasan_slab_free+0x10a/0x190
 __kmem_cache_free+0xca/0x3f0
 cifs_put_tcp_session+0x30c/0x450
 cifs_mount+0xf95/0x1970
 cifs_smb3_do_mount+0x295/0x1660
 smb3_get_tree+0x352/0x5e0
 vfs_get_tree+0x8e/0x2e0
 path_mount+0xf8c/0x1990
 do_mount+0xee/0x110
 __x64_sys_mount+0x14b/0x1f0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff888108f35380
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 0 bytes inside of
 16-byte region [ffff888108f35380, ffff888108f35390)
The buggy address belongs to the physical page:
page:00000000333f8e58 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888108f350e0 pfn:0x108f35
flags: 0x200000000000200(slab|node=0|zone=2)
raw: 0200000000000200 0000000000000000 dead000000000122 ffff8881000423c0
raw: ffff888108f350e0 000000008080007a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff888108f35280: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
 ffff888108f35300: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
>ffff888108f35380: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc
                   ^
 ffff888108f35400: fa fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888108f35480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 7be3248f3139 ("cifs: To match file servers, make sure the server hostname matches")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>