---[ end trace a539408211b94d57 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:753 Read of size 4 at addr ffff888111d63110 by task syz-executor/287 CPU: 1 PID: 287 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 fast_dput+0x1e0/0x290 fs/dcache.c:753 dput+0x26/0x90 fs/dcache.c:880 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1149 __cleanup_mnt+0x19/0x20 fs/namespace.c:1156 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff438c9c257 Code: a2 c7 05 9c 44 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffee143cce8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff438c9c257 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffee143cda0 RBP: 00007ffee143cda0 R08: 00007ffee143dda0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffee143de30 R13: 00007ff438d3145c R14: 000000000000f568 R15: 00007ffee143de70 Allocated by task 1430: 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:433 [inline] __kasan_slab_alloc+0xb7/0xe0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 __d_alloc+0x2d/0x690 fs/dcache.c:1749 d_alloc fs/dcache.c:1828 [inline] d_alloc_parallel+0xe5/0x1380 fs/dcache.c:2584 __lookup_slow+0x14c/0x410 fs/namei.c:1656 lookup_one_len+0x19d/0x2d0 fs/namei.c:2726 incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210 open_or_create_special_dir+0x4c/0x1f0 fs/incfs/vfs.c:475 incfs_mount_fs+0x42f/0x890 fs/incfs/vfs.c:1884 legacy_get_tree+0xed/0x190 fs/fs_context.c:611 vfs_get_tree+0x89/0x260 fs/super.c:1530 do_new_mount+0x251/0xb40 fs/namespace.c:3037 path_mount+0x640/0xff0 fs/namespace.c:3367 do_mount fs/namespace.c:3380 [inline] __do_sys_mount fs/namespace.c:3588 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3565 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3565 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 1456: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 __d_free+0x23/0x30 fs/dcache.c:273 rcu_do_batch+0x4c1/0xbf0 kernel/rcu/tree.c:2523 rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq kernel/softirq.c:621 [inline] invoke_softirq kernel/softirq.c:443 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x516/0x660 fs/dcache.c:600 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x47/0x90 fs/dcache.c:893 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1149 __cleanup_mnt+0x19/0x20 fs/namespace.c:1156 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 __call_rcu_common kernel/rcu/tree.c:3011 [inline] call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x516/0x660 fs/dcache.c:600 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x47/0x90 fs/dcache.c:893 handle_mounts fs/namei.c:1514 [inline] step_into+0x8f8/0xce0 fs/namei.c:1814 open_last_lookups fs/namei.c:3563 [inline] path_openat+0xf69/0x2f80 fs/namei.c:3747 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236 do_sys_open fs/open.c:1252 [inline] __do_sys_openat fs/open.c:1268 [inline] __se_sys_openat fs/open.c:1263 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1263 x64_sys_call+0x219/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff888111d63110 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff888111d63110, ffff888111d631e0) The buggy address belongs to the page: page:ffffea00044758c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111d63 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 dead000000000100 dead000000000122 ffff8881001c4000 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 226, ts 15499636973, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 __d_alloc+0x2d/0x690 fs/dcache.c:1749 d_alloc fs/dcache.c:1828 [inline] d_alloc_parallel+0xe5/0x1380 fs/dcache.c:2584 __lookup_slow+0x14c/0x410 fs/namei.c:1656 lookup_slow+0x57/0x70 fs/namei.c:1688 walk_component+0x326/0x460 fs/namei.c:1984 link_path_walk+0x688/0xde0 fs/namei.c:-1 path_openat+0x282/0x2f80 fs/namei.c:3746 do_filp_open+0x1df/0x400 fs/namei.c:3777 page_owner free stack trace missing Memory state around the buggy address: ffff888111d63000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111d63080: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc >ffff888111d63100: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888111d63180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888111d63200: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 0 PID: 287 at fs/dcache.c:769 fast_dput+0x207/0x290 fs/dcache.c:769 Modules linked in: CPU: 0 PID: 287 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:769 Code: ec f2 ff e9 4e fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a1 fe ff ff 48 89 df e8 53 ec f2 ff e9 94 fe ff ff e8 f9 7c b3 ff <0f> 0b e9 13 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ec fe ff RSP: 0018:ffffc900009c7ce0 EFLAGS: 00010293 RAX: ffffffff81b639e7 RBX: ffff888111d63110 RCX: ffff88811f6ccf00 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc900009c7d08 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000138f8c R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff888111d63168 R15: 1ffff110223ac62d FS: 0000555569353500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 00000001257c9000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dput+0x26/0x90 fs/dcache.c:880 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1af/0x210 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1149 __cleanup_mnt+0x19/0x20 fs/namespace.c:1156 task_work_run+0x127/0x190 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff438c9c257 Code: a2 c7 05 9c 44 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffee143cce8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff438c9c257 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffee143cda0 RBP: 00007ffee143cda0 R08: 00007ffee143dda0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffee143de30 R13: 00007ff438d3145c R14: 000000000000f568 R15: 00007ffee143de70 ---[ end trace a539408211b94d58 ]--- ------------[ cut here ]------------ WARNING: CPU: 0 PID: 287 at fs/inode.c:335 drop_nlink+0xc5/0x110 fs/inode.c:335 Modules linked in: CPU: 0 PID: 287 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:335 Code: 1b 48 8d bb b8 04 00 00 be 08 00 00 00 e8 c3 0b f2 ff f0 48 ff 83 b8 04 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 3b 9a b2 ff <0f> 0b eb 86 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5e ff ff ff 4c RSP: 0018:ffffc900009c7d60 EFLAGS: 00010293 RAX: ffffffff81b71ca5 RBX: ffff888127c82e88 RCX: ffff88811f6ccf00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900009c7d88 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000138f9c R12: dffffc0000000000 R13: 1ffff11024f905da R14: ffff888127c82ed0 R15: 0000000000000000 FS: 0000555569353500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a70521ce70 CR3: 00000001257c9000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: shmem_rmdir+0x5b/0x90 mm/shmem.c:2968 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_unlinkat fs/namei.c:4398 [inline] __se_sys_unlinkat fs/namei.c:4392 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4392 x64_sys_call+0x4c0/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff438c9a137 Code: 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 07 01 00 00 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:00007ffee143cce8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007ff438c9a137 RDX: 0000000000000200 RSI: 00007ffee143de30 RDI: 00000000ffffff9c RBP: 00007ff438d3145c R08: 0000000000018700 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffee143de30 R13: 00007ff438d3145c R14: 000000000000f568 R15: 00007ffee143de70 ---[ end trace a539408211b94d59 ]---