==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1f2/0x2a0 fs/dcache.c:750
Read of size 4 at addr ffff888123d1e660 by task syz-executor/568

CPU: 0 PID: 568 Comm: syz-executor Tainted: G        W         5.10.226-syzkaller-00709-ge5e5644ea27f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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:750
 dput+0x21/0x80 fs/dcache.c:870
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1979
 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:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274
 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7642d5b327
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffff26c4f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7642dcc134 RCX: 00007f7642d5b327
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffff26c5040
RBP: 00007ffff26c5040 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffff26c60c0
R13: 00007f7642dcc134 R14: 00000000000099a2 R15: 00007ffff26c6100

Allocated by task 573:
 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:1714
 d_alloc fs/dcache.c:1793 [inline]
 d_alloc_parallel+0xec/0x1370 fs/dcache.c:2547
 __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:469
 incfs_mount_fs+0x48d/0xa10 fs/incfs/vfs.c:1867
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:593
 vfs_get_tree+0x88/0x290 fs/super.c:1570
 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 19:
 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:597
 dentry_kill+0xc0/0x2a0
 dput+0x40/0x80 fs/dcache.c:883
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1979
 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:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274
 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56
 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:597
 dentry_kill+0xc0/0x2a0
 dput+0x40/0x80 fs/dcache.c:883
 __lookup_slow+0x389/0x400 fs/namei.c:1643
 lookup_one_len+0x180/0x2c0 fs/namei.c:2656
 ovl_check_whiteouts fs/overlayfs/readdir.c:281 [inline]
 ovl_dir_read+0x3d4/0x530 fs/overlayfs/readdir.c:315
 ovl_dir_read_merged+0x268/0x530 fs/overlayfs/readdir.c:362
 ovl_cache_get fs/overlayfs/readdir.c:414 [inline]
 ovl_iterate+0x103b/0x2070 fs/overlayfs/readdir.c:762
 iterate_dir+0x265/0x580
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888123d1e660
 which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
 208-byte region [ffff888123d1e660, ffff888123d1e730)
The buggy address belongs to the page:
page:ffffea00048f4780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x123d1e
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea00048f4740 0000000600000006 ffff888100193800
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 0x112cd0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 345, ts 22988479456, 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:1714
 d_alloc fs/dcache.c:1793 [inline]
 d_alloc_parallel+0xec/0x1370 fs/dcache.c:2547
 __lookup_slow+0x154/0x400 fs/namei.c:1625
 lookup_one_len+0x180/0x2c0 fs/namei.c:2656
 ovl_check_whiteouts fs/overlayfs/readdir.c:281 [inline]
 ovl_dir_read+0x3d4/0x530 fs/overlayfs/readdir.c:315
 ovl_dir_read_merged+0x268/0x530 fs/overlayfs/readdir.c:362
 ovl_cache_get fs/overlayfs/readdir.c:414 [inline]
 ovl_iterate+0x103b/0x2070 fs/overlayfs/readdir.c:762
 iterate_dir+0x265/0x580
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888123d1e500: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
 ffff888123d1e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888123d1e600: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
                                                       ^
 ffff888123d1e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888123d1e700: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 568 at fs/dcache.c:766 fast_dput+0x256/0x2a0 fs/dcache.c:766
Modules linked in:
CPU: 0 PID: 568 Comm: syz-executor Tainted: G    B   W         5.10.226-syzkaller-00709-ge5e5644ea27f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:fast_dput+0x256/0x2a0 fs/dcache.c:766
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 44 bb f1 ff e9 ea fe ff ff e8 da 20 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:ffffc90000d17cd8 EFLAGS: 00010293
RAX: ffffffff81b68c16 RBX: ffff888123d1e6bc RCX: ffff88811e6d3b40
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc90000d17d10 R08: ffffffff81b68b6b R09: 0000000000000003
R10: fffff520001a2f8c R11: dffffc0000000001 R12: 00000000ffffff80
R13: ffff888123d1e660 R14: ffff888123d1e6b8 R15: dffffc0000000000
FS:  0000555581495500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555814b04a8 CR3: 000000012587c000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dput+0x21/0x80 fs/dcache.c:870
 incfs_free_mount_info+0x60/0x210 fs/incfs/data_mgmt.c:166
 incfs_kill_sb+0x1c2/0x220 fs/incfs/vfs.c:1979
 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:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xbf/0xd0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0xa2/0x1a0 kernel/entry/common.c:274
 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7642d5b327
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffff26c4f88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f7642dcc134 RCX: 00007f7642d5b327
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffff26c5040
RBP: 00007ffff26c5040 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000202 R12: 00007ffff26c60c0
R13: 00007f7642dcc134 R14: 00000000000099a2 R15: 00007ffff26c6100
---[ end trace 948354dbf377adb5 ]---