KASAN: slab-use-after-free Read in cifs_crypto_secmech_release

Status: moderation: reported on 2026/10/19 21:11
Subsystems: cifs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+847937b554ec2a5a9bbb@syzkaller.appspotmail.com
First crash: 4d01h, last: 4d01h
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
2f0bb5eb assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: slab-use-after-free Read in cifs_crypto_secmech_release 2026/10/17 00:56 2026/10/17 00:56 2026/10/17 01:49 432c0077
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 KASAN: slab-use-after-free Write in cifs_crypto_secmech_release 22 syz, C 5 16d 31d 0/2 upstream: reported C repro on 2026/09/18 05:37

Sample crash report:
CIFS: VFS: \\172.20.20.170 Error -512 sending data on socket to server
==================================================================
BUG: KASAN: slab-use-after-free in cifs_crypto_secmech_release+0xed/0x120 fs/smb/client/cifsencrypt.c:512
Read of size 8 at addr ffff8880526ec490 by task syz.3.92/6393

CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 cifs_crypto_secmech_release+0xed/0x120 fs/smb/client/cifsencrypt.c:512
 cifs_put_tcp_session+0x240/0x3e0 fs/smb/client/connect.c:1740
 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554
 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35d7b9e559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559
RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200
RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8
 </TASK>

Allocated by task 6393:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6394:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6802
 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153
 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880526ec000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1168 bytes inside of
 freed 4096-byte region [ffff8880526ec000, ffff8880526ed000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
page last free pid 6391 tgid 6385 ts 189990448004 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543
 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981
 io_alloc_req io_uring/io_uring.h:537 [inline]
 io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039
 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880526ec380: fb fb fb fb fb fb fb f
 ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in cifs_crypto_secmech_release+0xfa/0x120 fs/smb/client/cifsencrypt.c:516
Read of size 8 at addr ffff8880526ec498 by task syz.3.92/6393

CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G    B               syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 cifs_crypto_secmech_release+0xfa/0x120 fs/smb/client/cifsencrypt.c:516
 cifs_put_tcp_session+0x240/0x3e0 fs/smb/client/connect.c:1740
 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554
 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35d7b9e559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559
RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200
RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8
 </TASK>

Allocated by task 6393:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6394:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6802
 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153
 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880526ec000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1176 bytes inside of
 freed 4096-byte region [ffff8880526ec000, ffff8880526ed000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
page last free pid 6391 tgid 6385 ts 189990448004 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543
 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981
 io_alloc_req io_uring/io_uring.h:537 [inline]
 io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039
 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in cifs_put_tcp_session+0x374/0x3e0 fs/smb/client/connect.c:1742
Read of size 8 at addr ffff8880526ec470 by task syz.3.92/6393

CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G    B               syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 cifs_put_tcp_session+0x374/0x3e0 fs/smb/client/connect.c:1742
 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554
 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35d7b9e559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559
RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200
RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8
 </TASK>

Allocated by task 6393:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6394:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6802
 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153
 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880526ec000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1136 bytes inside of
 freed 4096-byte region [ffff8880526ec000, ffff8880526ed000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
page last free pid 6391 tgid 6385 ts 189990448004 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543
 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981
 io_alloc_req io_uring/io_uring.h:537 [inline]
 io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039
 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880526ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: slab-use-after-free in cifs_put_tcp_session+0x381/0x3e0 fs/smb/client/connect.c:1743
Write of size 8 at addr ffff8880526ec470 by task syz.3.92/6393

CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G    B               syzkaller #0 PREEMPT(full) 
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 cifs_put_tcp_session+0x381/0x3e0 fs/smb/client/connect.c:1743
 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554
 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35d7b9e559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559
RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200
RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8
 </TASK>

Allocated by task 6393:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6394:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6802
 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153
 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880526ec000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1136 bytes inside of
 freed 4096-byte region [ffff8880526ec000, ffff8880526ed000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801d035140 dead000000000100 dead000000000122
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765
 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579
 get_session fs/smb/client/dfs.c:65 [inline]
 dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275
 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3869
 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026
 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline]
 smb3_get_tree fs/smb/client/fs_context.c:917 [inline]
 smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1278 [inline]
 do_new_mount_fc fs/namespace.c:3885 [inline]
 do_new_mount fs/namespace.c:3961 [inline]
 path_mount+0x7d0/0x2850 fs/namespace.c:4312
 do_mount fs/namespace.c:4325 [inline]
 __do_sys_mount fs/namespace.c:4543 [inline]
 __se_sys_mount fs/namespace.c:4520 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4520
page last free pid 6391 tgid 6385 ts 189990448004 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543
 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981
 io_alloc_req io_uring/io_uring.h:537 [inline]
 io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039
 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880526ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/15 21:03 upstream 045958acaa75 3f2522c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root KASAN: slab-use-after-free Read in cifs_crypto_secmech_release
* Struck through repros no longer work on HEAD.