CVE-2024-53177

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

smb: prevent use-after-free due to open_cached_dir error paths

If open_cached_dir() encounters an error parsing the lease from the

server, the error handling may race with receiving a lease break,

resulting in open_cached_dir() freeing the cfid while the queued work is

pending.

Update open_cached_dir() to drop refs rather than directly freeing the

cfid.

Have cached_dir_lease_break(), cfids_laundromat_worker(), and

invalidate_all_cached_dirs() clear has_lease immediately while still

holding cfids->cfid_list_lock, and then use this to also simplify the

reference counting in cfids_laundromat_worker() and

invalidate_all_cached_dirs().

Fixes this KASAN splat (which manually injects an error and lease break

in open_cached_dir()):

==================================================================

BUG: KASAN: slab-use-after-free in smb2_cached_lease_break+0x27/0xb0

Read of size 8 at addr ffff88811cc24c10 by task kworker/3:1/65

CPU: 3 UID: 0 PID: 65 Comm: kworker/3:1 Not tainted 6.12.0-rc6-g255cf264e6e5-dirty #87

Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020

Workqueue: cifsiod smb2_cached_lease_break

Call Trace:

<TASK>

dump_stack_lvl+0x77/0xb0

print_report+0xce/0x660

kasan_report+0xd3/0x110

smb2_cached_lease_break+0x27/0xb0

process_one_work+0x50a/0xc50

worker_thread+0x2ba/0x530

kthread+0x17c/0x1c0

ret_from_fork+0x34/0x60

ret_from_fork_asm+0x1a/0x30

</TASK>

Allocated by task 2464:

kasan_save_stack+0x33/0x60

kasan_save_track+0x14/0x30

__kasan_kmalloc+0xaa/0xb0

open_cached_dir+0xa7d/0x1fb0

smb2_query_path_info+0x43c/0x6e0

cifs_get_fattr+0x346/0xf10

cifs_get_inode_info+0x157/0x210

cifs_revalidate_dentry_attr+0x2d1/0x460

cifs_getattr+0x173/0x470

vfs_statx_path+0x10f/0x160

vfs_statx+0xe9/0x150

vfs_fstatat+0x5e/0xc0

__do_sys_newfstatat+0x91/0xf0

do_syscall_64+0x95/0x1a0

entry_SYSCALL_64_after_hwframe+0x76/0x7e

Freed by task 2464:

kasan_save_stack+0x33/0x60

kasan_save_track+0x14/0x30

kasan_save_free_info+0x3b/0x60

__kasan_slab_free+0x51/0x70

kfree+0x174/0x520

open_cached_dir+0x97f/0x1fb0

smb2_query_path_info+0x43c/0x6e0

cifs_get_fattr+0x346/0xf10

cifs_get_inode_info+0x157/0x210

cifs_revalidate_dentry_attr+0x2d1/0x460

cifs_getattr+0x173/0x470

vfs_statx_path+0x10f/0x160

vfs_statx+0xe9/0x150

vfs_fstatat+0x5e/0xc0

__do_sys_newfstatat+0x91/0xf0

do_syscall_64+0x95/0x1a0

entry_SYSCALL_64_after_hwframe+0x76/0x7e

Last potentially related work creation:

kasan_save_stack+0x33/0x60

__kasan_record_aux_stack+0xad/0xc0

insert_work+0x32/0x100

__queue_work+0x5c9/0x870

queue_work_on+0x82/0x90

open_cached_dir+0x1369/0x1fb0

smb2_query_path_info+0x43c/0x6e0

cifs_get_fattr+0x346/0xf10

cifs_get_inode_info+0x157/0x210

cifs_revalidate_dentry_attr+0x2d1/0x460

cifs_getattr+0x173/0x470

vfs_statx_path+0x10f/0x160

vfs_statx+0xe9/0x150

vfs_fstatat+0x5e/0xc0

__do_sys_newfstatat+0x91/0xf0

do_syscall_64+0x95/0x1a0

entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff88811cc24c00

which belongs to the cache kmalloc-1k of size 1024

The buggy address is located 16 bytes inside of

freed 1024-byte region [ffff88811cc24c00, ffff88811cc25000)