R13: 00007f7a9fc4e515 R14: 0000555555b034a8 R15: 000000000002db30
---[ end trace 46735b897ad6c384 ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1f2/0x2a0 fs/dcache.c:746
Read of size 4 at addr ffff8881104a6880 by task syz-executor/3649

CPU: 1 PID: 3649 Comm: syz-executor Tainted: G        W         5.10.218-syzkaller-00638-g3feee789f446 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 fast_dput+0x1f2/0x2a0 fs/dcache.c:746
 dput+0x21/0x80 fs/dcache.c:866
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1951
 deactivate_locked_super+0xad/0x110 fs/super.c:335
 deactivate_super+0xbe/0xf0 fs/super.c:366
 cleanup_mnt+0x45c/0x510 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x129/0x190 kernel/task_work.c:165
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xc83/0x2a50 kernel/exit.c:861
 do_group_exit+0x141/0x310 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:992
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7a9fbe0bd9
Code: Unable to access opcode bytes at RIP 0x7f7a9fbe0baf.
RSP: 002b:00007ffdd5ea61e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f7a9fc4e575 RCX: 00007f7a9fbe0bd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007ffdd5ea3f87 R09: 00007ffdd5ea74a0
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffdd5ea74a0
R13: 00007f7a9fc4e515 R14: 0000555555b034a8 R15: 000000000002db30

Allocated by task 4201:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xb1/0xe0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 __d_alloc+0x2d/0x6c0 fs/dcache.c:1710
 d_alloc fs/dcache.c:1789 [inline]
 d_alloc_parallel+0xec/0x1370 fs/dcache.c:2541
 __lookup_slow+0x154/0x400 fs/namei.c:1625
 lookup_one_len+0x180/0x2c0 fs/namei.c:2656
 incfs_lookup_dentry+0x5f/0xb0 fs/incfs/data_mgmt.c:210
 open_or_create_special_dir+0x4f/0x1d0 fs/incfs/vfs.c:448
 incfs_mount_fs+0x48d/0xa10 fs/incfs/vfs.c:1839
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1559
 do_new_mount+0x2ba/0xb30 fs/namespace.c:2910
 path_mount+0x56f/0xcb0 fs/namespace.c:3240
 do_mount fs/namespace.c:3253 [inline]
 __do_sys_mount fs/namespace.c:3461 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3438
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3438
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 3649:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0xa9/0x1e0 mm/slub.c:3219
 __d_free+0x23/0x30 fs/dcache.c:271
 rcu_do_batch+0x597/0xc40 kernel/rcu/tree.c:2494
 rcu_core+0x5ad/0xe40 kernel/rcu/tree.c:2735
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748
 __do_softirq+0x268/0x5bb kernel/softirq.c:309

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd3/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x135/0x11f0 kernel/rcu/tree.c:3050
 dentry_free+0xbf/0x160
 __dentry_kill+0x505/0x650 fs/dcache.c:593
 dentry_kill+0xc0/0x2a0
 dput+0x40/0x80 fs/dcache.c:879
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1951
 deactivate_locked_super+0xad/0x110 fs/super.c:335
 deactivate_super+0xbe/0xf0 fs/super.c:366
 cleanup_mnt+0x45c/0x510 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x129/0x190 kernel/task_work.c:165
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xc83/0x2a50 kernel/exit.c:861
 do_group_exit+0x141/0x310 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:992
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Second to last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd3/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x135/0x11f0 kernel/rcu/tree.c:3050
 dentry_free+0xbf/0x160
 __dentry_kill+0x505/0x650 fs/dcache.c:593
 dentry_kill+0xc0/0x2a0
 dput+0x40/0x80 fs/dcache.c:879
 do_unlinkat+0x44d/0x8b0 fs/namei.c:4038
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff8881104a6880
 which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
 208-byte region [ffff8881104a6880, ffff8881104a6950)
The buggy address belongs to the page:
page:ffffea0004412980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1104a6
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea00044103c0 0000000400000004 ffff888100193500
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x12cd0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 108, ts 3597393690, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5348
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1b9/0x2e0 mm/slub.c:2960
 __d_alloc+0x2d/0x6c0 fs/dcache.c:1710
 d_alloc+0x4b/0x1d0 fs/dcache.c:1789
 __lookup_hash+0xe7/0x290 fs/namei.c:1537
 do_unlinkat+0x28b/0x8b0 fs/namei.c:4023
 __do_sys_unlink fs/namei.c:4082 [inline]
 __se_sys_unlink fs/namei.c:4080 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4080
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881104a6780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881104a6800: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8881104a6880: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881104a6900: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
 ffff8881104a6980: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3649 at fs/dcache.c:762 fast_dput+0x256/0x2a0 fs/dcache.c:762
Modules linked in:
CPU: 1 PID: 3649 Comm: syz-executor Tainted: G    B   W         5.10.218-syzkaller-00638-g3feee789f446 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:fast_dput+0x256/0x2a0 fs/dcache.c:762
Code: f1 ff e9 d4 fe ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c f7 fe ff ff 4c 89 ef e8 c4 bc f1 ff e9 ea fe ff ff e8 8a 28 b4 ff <0f> 0b e9 c0 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 2a ff ff
RSP: 0018:ffffc90001227b20 EFLAGS: 00010293
RAX: ffffffff81b681f6 RBX: ffff8881104a68dc RCX: ffff888122d5bb40
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90001227b58 R08: ffffffff81b6814b R09: 0000000000000003
R10: fffff52000244f54 R11: dffffc0000000001 R12: 00000000ffffff80
R13: ffff8881104a6880 R14: ffff8881104a68d8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb982423a6c CR3: 000000010bac4000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dput+0x21/0x80 fs/dcache.c:866
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1951
 deactivate_locked_super+0xad/0x110 fs/super.c:335
 deactivate_super+0xbe/0xf0 fs/super.c:366
 cleanup_mnt+0x45c/0x510 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x129/0x190 kernel/task_work.c:165
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xc83/0x2a50 kernel/exit.c:861
 do_group_exit+0x141/0x310 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:992
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7a9fbe0bd9
Code: Unable to access opcode bytes at RIP 0x7f7a9fbe0baf.
RSP: 002b:00007ffdd5ea61e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f7a9fc4e575 RCX: 00007f7a9fbe0bd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000009 R08: 00007ffdd5ea3f87 R09: 00007ffdd5ea74a0
R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffdd5ea74a0
R13: 00007f7a9fc4e515 R14: 0000555555b034a8 R15: 000000000002db30
---[ end trace 46735b897ad6c385 ]---