---[ end trace 0000000000000000 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:778 Read of size 4 at addr ffff888132ef7880 by task syz-executor/284 CPU: 1 PID: 284 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 fast_dput+0x1e9/0x290 fs/dcache.c:778 dput+0x21/0x80 fs/dcache.c:905 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:2003 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x474/0x500 fs/namespace.c:1191 __cleanup_mnt+0x19/0x20 fs/namespace.c:1198 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa35/0x2660 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 __do_sys_exit_group kernel/exit.c:1039 [inline] __se_sys_exit_group kernel/exit.c:1037 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f654659c799 Code: Unable to access opcode bytes at 0x7f654659c76f. RSP: 002b:00007fff6d2e65d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6546631ff0 RCX: 00007f654659c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6546631f90 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff6d2e7890 R13: 00007f6546631f90 R14: 000055558e4584e8 R15: 00007fff6d2e8960 Allocated by task 1923: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:334 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc_lru+0x104/0x280 mm/slub.c:3415 __d_alloc+0x34/0x6c0 fs/dcache.c:1774 d_alloc fs/dcache.c:1854 [inline] d_alloc_parallel+0xe2/0x12e0 fs/dcache.c:2647 __lookup_slow+0x14f/0x410 fs/namei.c:1682 lookup_one_len+0x19d/0x2e0 fs/namei.c:2747 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/0x890 fs/incfs/vfs.c:1890 legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632 vfs_get_tree+0x9a/0x270 fs/super.c:1575 do_new_mount+0x25a/0xa20 fs/namespace.c:3078 path_mount+0x659/0xfc0 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3606 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 19: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:242 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:250 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1750 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776 slab_free mm/slub.c:3712 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3737 __d_free+0x23/0x30 fs/dcache.c:298 rcu_do_batch+0x52a/0xbc0 kernel/rcu/tree.c:2297 rcu_core+0x5c3/0xe80 kernel/rcu/tree.c:2557 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq+0xb/0xd kernel/softirq.c:680 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf90 kernel/rcu/tree.c:2926 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x529/0x670 fs/dcache.c:625 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:2003 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x474/0x500 fs/namespace.c:1191 __cleanup_mnt+0x19/0x20 fs/namespace.c:1198 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa35/0x2660 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 __do_sys_exit_group kernel/exit.c:1039 [inline] __se_sys_exit_group kernel/exit.c:1037 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf90 kernel/rcu/tree.c:2926 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x529/0x670 fs/dcache.c:625 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 dcache_dir_close+0x3b/0x40 fs/libfs.c:91 __fput+0x1fc/0x8f0 fs/file_table.c:320 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888132ef7880 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff888132ef7880, ffff888132ef7950) The buggy address belongs to the physical page: page:ffffea0004cbbdc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x132ef7 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea0004cbe3c0 dead000000000003 ffff8881001ed380 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 741, tgid 736 (syz.1.113), ts 36920109404, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670 prep_new_page+0x1c/0x110 mm/page_alloc.c:2677 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5897 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3d0 mm/slub.c:2020 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc_lru+0x144/0x280 mm/slub.c:3415 __d_alloc+0x34/0x6c0 fs/dcache.c:1774 d_alloc fs/dcache.c:1854 [inline] d_alloc_parallel+0xe2/0x12e0 fs/dcache.c:2647 __lookup_slow+0x14f/0x410 fs/namei.c:1682 lookup_one+0x19a/0x2e0 fs/namei.c:2777 ovl_lookup_upper fs/overlayfs/overlayfs.h:329 [inline] ovl_workdir_create+0x1da/0x6d0 fs/overlayfs/super.c:794 ovl_get_indexdir+0x210/0x5e0 fs/overlayfs/super.c:1592 ovl_fill_super+0x1b54/0x2a20 fs/overlayfs/super.c:2141 page_owner free stack trace missing Memory state around the buggy address: ffff888132ef7780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888132ef7800: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888132ef7880: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888132ef7900: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff888132ef7980: fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 284 at fs/dcache.c:794 fast_dput+0x210/0x290 fs/dcache.c:794 Modules linked in: CPU: 1 PID: 284 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:794 Code: a0 f1 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 7a a0 f1 ff e9 8c fe ff ff e8 20 6e ac 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:ffffc90000e27ad0 EFLAGS: 00010293 RAX: ffffffff81c4fee0 RBX: ffff888132ef7880 RCX: ffff88810b96e540 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000e27b00 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520001c4f4c R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff888132ef78d8 R15: 1ffff110265def1b FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001000 CR3: 000000011993c000 CR4: 00000000003526a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dput+0x21/0x80 fs/dcache.c:905 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:2003 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x474/0x500 fs/namespace.c:1191 __cleanup_mnt+0x19/0x20 fs/namespace.c:1198 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa35/0x2660 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 __do_sys_exit_group kernel/exit.c:1039 [inline] __se_sys_exit_group kernel/exit.c:1037 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f654659c799 Code: Unable to access opcode bytes at 0x7f654659c76f. RSP: 002b:00007fff6d2e65d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6546631ff0 RCX: 00007f654659c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6546631f90 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff6d2e7890 R13: 00007f6546631f90 R14: 000055558e4584e8 R15: 00007fff6d2e8960 ---[ end trace 0000000000000000 ]--- list_del corruption. prev->next should be ffff888132ef7b30, but was ffff888132ef7a20. (prev=ffff888111a31f70) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:61! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 284 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59 Code: e8 7e 6b 88 02 0f 0b 48 c7 c7 e0 7b ca 85 48 89 de e8 6d 6b 88 02 0f 0b 48 c7 c7 40 7c ca 85 48 89 de 4c 89 f9 e8 59 6b 88 02 <0f> 0b 48 c7 c7 c0 7c ca 85 48 89 de 4c 89 f1 e8 45 6b 88 02 0f 0b RSP: 0018:ffffc90000e27a48 EFLAGS: 00010246 RAX: 000000000000006d RBX: ffff888132ef7b30 RCX: 8833ee8cb2676900 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc90000e27a68 R08: ffffc90000e27747 R09: 1ffff920001c4ee8 R10: dffffc0000000000 R11: fffff520001c4ee9 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888132ef7a20 R15: ffff888111a31f70 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2a1e7e9e80 CR3: 000000012a81f000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:134 [inline] dentry_unlist fs/dcache.c:554 [inline] __dentry_kill+0x25d/0x670 fs/dcache.c:607 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 incfs_free_mount_info+0x80/0x200 fs/incfs/data_mgmt.c:167 incfs_kill_sb+0x1b8/0x220 fs/incfs/vfs.c:2003 deactivate_locked_super+0xb5/0x120 fs/super.c:334 deactivate_super+0xaf/0xe0 fs/super.c:365 cleanup_mnt+0x474/0x500 fs/namespace.c:1191 __cleanup_mnt+0x19/0x20 fs/namespace.c:1198 task_work_run+0x1e1/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa35/0x2660 kernel/exit.c:886 do_group_exit+0x210/0x2d0 kernel/exit.c:1028 __do_sys_exit_group kernel/exit.c:1039 [inline] __se_sys_exit_group kernel/exit.c:1037 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f654659c799 Code: Unable to access opcode bytes at 0x7f654659c76f. RSP: 002b:00007fff6d2e65d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6546631ff0 RCX: 00007f654659c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6546631f90 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff6d2e7890 R13: 00007f6546631f90 R14: 000055558e4584e8 R15: 00007fff6d2e8960 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid+0x10f/0x130 lib/list_debug.c:59 Code: e8 7e 6b 88 02 0f 0b 48 c7 c7 e0 7b ca 85 48 89 de e8 6d 6b 88 02 0f 0b 48 c7 c7 40 7c ca 85 48 89 de 4c 89 f9 e8 59 6b 88 02 <0f> 0b 48 c7 c7 c0 7c ca 85 48 89 de 4c 89 f1 e8 45 6b 88 02 0f 0b RSP: 0018:ffffc90000e27a48 EFLAGS: 00010246 RAX: 000000000000006d RBX: ffff888132ef7b30 RCX: 8833ee8cb2676900 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc90000e27a68 R08: ffffc90000e27747 R09: 1ffff920001c4ee8 R10: dffffc0000000000 R11: fffff520001c4ee9 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888132ef7a20 R15: ffff888111a31f70 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2a1e7e9e80 CR3: 000000012a81f000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400