---[ end trace 8962c6484c46ea94 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:753 Read of size 4 at addr ffff888111cff000 by task syz-executor/19023 CPU: 1 PID: 19023 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 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+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 fast_dput+0x1e9/0x290 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+0x1b8/0x220 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1148 __cleanup_mnt+0x19/0x20 fs/namespace.c:1155 task_work_run+0x127/0x190 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7e/0x27a0 kernel/exit.c:889 do_group_exit+0x141/0x310 kernel/exit.c:1003 __do_sys_exit_group kernel/exit.c:1014 [inline] __se_sys_exit_group kernel/exit.c:1012 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012 x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fd3a64b4749 Code: Unable to access opcode bytes at RIP 0x7fd3a64b471f. RSP: 002b:00007ffdd9e7fcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fd3a6538ddd RCX: 00007fd3a64b4749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 00007ffdd9e7da97 R09: 00007ffdd9e80fb0 R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffdd9e80fb0 R13: 00007fd3a6538d7d R14: 000055556caba4a8 R15: 00007ffdd9e82080 Allocated by task 24579: 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+0xbd/0xf0 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/0x6a0 fs/dcache.c:1749 d_alloc fs/dcache.c:1828 [inline] d_alloc_parallel+0xe1/0x1380 fs/dcache.c:2584 __lookup_slow+0x13e/0x3e0 fs/namei.c:1656 lookup_one_len+0x195/0x2c0 fs/namei.c:2726 incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210 open_or_create_special_dir+0x4f/0x1d0 fs/incfs/vfs.c:475 incfs_mount_fs+0x42f/0x880 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+0x25a/0xa20 fs/namespace.c:3034 path_mount+0x675/0x1020 fs/namespace.c:3364 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3562 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3562 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 25: 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+0x51d/0xba0 kernel/rcu/tree.c:2523 rcu_core+0x5e4/0xf80 kernel/rcu/tree.c:2763 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776 handle_softirqs+0x250/0x560 kernel/softirq.c:583 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959 smpboot_thread_fn+0x45a/0x8c0 kernel/smpboot.c:164 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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+0x105/0xfe0 kernel/rcu/tree.c:3129 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x50a/0x650 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+0x1b8/0x220 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1148 __cleanup_mnt+0x19/0x20 fs/namespace.c:1155 task_work_run+0x127/0x190 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7e/0x27a0 kernel/exit.c:889 do_group_exit+0x141/0x310 kernel/exit.c:1003 __do_sys_exit_group kernel/exit.c:1014 [inline] __se_sys_exit_group kernel/exit.c:1012 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012 x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 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 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+0x105/0xfe0 kernel/rcu/tree.c:3129 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x50a/0x650 fs/dcache.c:600 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x47/0x90 fs/dcache.c:893 do_unlinkat+0x33f/0x6b0 fs/namei.c:4359 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4402 x64_sys_call+0x878/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:88 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 ffff888111cff000 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff888111cff000, ffff888111cff0d0) The buggy address belongs to the page: page:ffffea0004473fc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111cff flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004475140 0000000200000002 ffff8881001c5c80 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 103, ts 6392032112, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5808 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 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/0x6a0 fs/dcache.c:1749 d_alloc+0x4b/0x260 fs/dcache.c:1828 lookup_one_qstr_excl+0xcb/0x250 fs/namei.c:1567 filename_create+0x219/0x450 fs/namei.c:3844 do_symlinkat+0x65/0x5a0 fs/namei.c:4456 __do_sys_symlink fs/namei.c:4488 [inline] __se_sys_symlink fs/namei.c:4486 [inline] __x64_sys_symlink+0x7e/0x90 fs/namei.c:4486 x64_sys_call+0x759/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:89 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 page_owner free stack trace missing Memory state around the buggy address: ffff888111cfef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111cfef80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff888111cff000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888111cff080: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff888111cff100: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 19023 at fs/dcache.c:769 fast_dput+0x210/0x290 fs/dcache.c:769 Modules linked in: CPU: 1 PID: 19023 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:769 Code: 15 f3 ff e9 46 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 99 fe ff ff 48 89 df e8 ba 15 f3 ff e9 8c fe ff ff e8 20 93 b4 ff <0f> 0b e9 0b ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c e4 fe ff RSP: 0018:ffffc90000c17b40 EFLAGS: 00010293 RAX: ffffffff81b42c30 RBX: ffff888111cff000 RCX: ffff88810ecb13c0 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000c17b70 R08: 0000000000000004 R09: 0000000000000003 R10: fffff52000182f58 R11: 1ffff92000182f58 R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff888111cff058 R15: 1ffff1102239fe0b FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6dd99c5000 CR3: 000000010dc49000 CR4: 00000000003506a0 Call Trace: dput+0x26/0x90 fs/dcache.c:880 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:1997 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1148 __cleanup_mnt+0x19/0x20 fs/namespace.c:1155 task_work_run+0x127/0x190 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7e/0x27a0 kernel/exit.c:889 do_group_exit+0x141/0x310 kernel/exit.c:1003 __do_sys_exit_group kernel/exit.c:1014 [inline] __se_sys_exit_group kernel/exit.c:1012 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1012 x64_sys_call+0x832/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fd3a64b4749 Code: Unable to access opcode bytes at RIP 0x7fd3a64b471f. RSP: 002b:00007ffdd9e7fcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fd3a6538ddd RCX: 00007fd3a64b4749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 00007ffdd9e7da97 R09: 00007ffdd9e80fb0 R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffdd9e80fb0 R13: 00007fd3a6538d7d R14: 000055556caba4a8 R15: 00007ffdd9e82080 ---[ end trace 8962c6484c46ea95 ]---