Vulnerability CVE-2024-46796
Published: 2024-09-18

Description:
In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix double put of @cfile in smb2_set_path_size()

If smb2_compound_op() is called with a valid @cfile and returned
-EINVAL, we need to call cifs_get_writable_path() before retrying it
as the reference of @cfile was already dropped by previous call.

This fixes the following KASAN splat when running fstests generic/013
against Windows Server 2022:

CIFS: Attempting to mount //w22-fs0/scratch
run fstests generic/013 at 2024-09-02 19:48:59
==================================================================
BUG: KASAN: slab-use-after-free in detach_if_pending+0xab/0x200
Write of size 8 at addr ffff88811f1a3730 by task kworker/3:2/176

CPU: 3 UID: 0 PID: 176 Comm: kworker/3:2 Not tainted 6.11.0-rc6 #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40
04/01/2014
Workqueue: cifsoplockd cifs_oplock_break [cifs]
Call Trace:
<TASK>
dump_stack_lvl+0x5d/0x80
? detach_if_pending+0xab/0x200
print_report+0x156/0x4d9
? detach_if_pending+0xab/0x200
? __virt_addr_valid+0x145/0x300
? __phys_addr+0x46/0x90
? detach_if_pending+0xab/0x200
kasan_report+0xda/0x110
? detach_if_pending+0xab/0x200
detach_if_pending+0xab/0x200
timer_delete+0x96/0xe0
? __pfx_timer_delete+0x10/0x10
? rcu_is_watching+0x20/0x50
try_to_grab_pending+0x46/0x3b0
__cancel_work+0x89/0x1b0
? __pfx___cancel_work+0x10/0x10
? kasan_save_track+0x14/0x30
cifs_close_deferred_file+0x110/0x2c0 [cifs]
? __pfx_cifs_close_deferred_file+0x10/0x10 [cifs]
? __pfx_down_read+0x10/0x10
cifs_oplock_break+0x4c1/0xa50 [cifs]
? __pfx_cifs_oplock_break+0x10/0x10 [cifs]
? lock_is_held_type+0x85/0xf0
? mark_held_locks+0x1a/0x90
process_one_work+0x4c6/0x9f0
? find_held_lock+0x8a/0xa0
? __pfx_process_one_work+0x10/0x10
? lock_acquired+0x220/0x550
? __list_add_valid_or_report+0x37/0x100
worker_thread+0x2e4/0x570
? __kthread_parkme+0xd1/0xf0
? __pfx_worker_thread+0x10/0x10
kthread+0x17f/0x1c0
? kthread+0xda/0x1c0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x31/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>

Allocated by task 1118:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
cifs_new_fileinfo+0xc8/0x9d0 [cifs]
cifs_atomic_open+0x467/0x770 [cifs]
lookup_open.isra.0+0x665/0x8b0
path_openat+0x4c3/0x1380
do_filp_open+0x167/0x270
do_sys_openat2+0x129/0x160
__x64_sys_creat+0xad/0xe0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 83:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
poison_slab_object+0xe9/0x160
__kasan_slab_free+0x32/0x50
kfree+0xf2/0x300
process_one_work+0x4c6/0x9f0
worker_thread+0x2e4/0x570
kthread+0x17f/0x1c0
ret_from_fork+0x31/0x60
ret_from_fork_asm+0x1a/0x30

Last potentially related work creation:
kasan_save_stack+0x30/0x50
__kasan_record_aux_stack+0xad/0xc0
insert_work+0x29/0xe0
__queue_work+0x5ea/0x760
queue_work_on+0x6d/0x90
_cifsFileInfo_put+0x3f6/0x770 [cifs]
smb2_compound_op+0x911/0x3940 [cifs]
smb2_set_path_size+0x228/0x270 [cifs]
cifs_set_file_size+0x197/0x460 [cifs]
cifs_setattr+0xd9c/0x14b0 [cifs]
notify_change+0x4e3/0x740
do_truncate+0xfa/0x180
vfs_truncate+0x195/0x200
__x64_sys_truncate+0x109/0x150
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f

 References:
https://git.kernel.org/stable/c/5a72d1edb0843e4c927a4096f81e631031c25c28
https://git.kernel.org/stable/c/762099898309218b4a7954f3d49e985dc4dfd638
https://git.kernel.org/stable/c/f9c169b51b6ce20394594ef674d6b10efba31220
Copyright 2026, cxsecurity.com

 

Back to Top