RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6f46f74f63 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7cd67590 R13: 00007f6f46f74f63 R14: 00005555727e04e8 R15: 00007ffe7cd68660 ---[ end trace a3795bd3cdbee639 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:750 Read of size 4 at addr ffff88811a4d5dd0 by task syz-executor/10440 CPU: 0 PID: 10440 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 fast_dput+0x1e0/0x290 fs/dcache.c:750 dput+0x21/0x80 fs/dcache.c:870 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1a1/0x200 fs/incfs/vfs.c:1981 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7c/0x24e0 kernel/exit.c:879 do_group_exit+0x149/0x310 kernel/exit.c:993 __do_sys_exit_group kernel/exit.c:1004 [inline] __se_sys_exit_group kernel/exit.c:1002 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1002 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6f46ede559 Code: Unable to access opcode bytes at RIP 0x7f6f46ede52f. RSP: 002b:00007ffe7cd662d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6f46f74fc3 RCX: 00007f6f46ede559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6f46f74f63 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7cd67590 R13: 00007f6f46f74f63 R14: 00005555727e04e8 R15: 00007ffe7cd68660 Allocated by task 10566: 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+0xb7/0xe0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x15a/0x2d0 mm/slub.c:2965 __d_alloc+0x2d/0x690 fs/dcache.c:1714 d_alloc fs/dcache.c:1793 [inline] d_alloc_parallel+0xe2/0x1390 fs/dcache.c:2549 __lookup_slow+0x14c/0x410 fs/namei.c:1633 lookup_one_len+0x196/0x2d0 fs/namei.c:2706 incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210 open_or_create_special_dir+0x4c/0x1e0 fs/incfs/vfs.c:471 incfs_mount_fs+0x434/0x8d0 fs/incfs/vfs.c:1869 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1583 do_new_mount+0x25a/0xa30 fs/namespace.c:3006 path_mount+0x581/0xca0 fs/namespace.c:3336 do_mount fs/namespace.c:3349 [inline] __do_sys_mount fs/namespace.c:3557 [inline] __se_sys_mount+0x320/0x390 fs/namespace.c:3534 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 10599: 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: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:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kmem_cache_free+0x100/0x2d0 mm/slub.c:3224 __d_free+0x23/0x30 fs/dcache.c:271 rcu_do_batch+0x488/0xaf0 kernel/rcu/tree.c:2494 rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 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 kernel/rcu/tree.c:2980 [inline] call_rcu+0x11a/0x1090 kernel/rcu/tree.c:3054 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x516/0x660 fs/dcache.c:597 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:883 incfs_free_mount_info+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1a1/0x200 fs/incfs/vfs.c:1981 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7c/0x24e0 kernel/exit.c:879 do_group_exit+0x149/0x310 kernel/exit.c:993 __do_sys_exit_group kernel/exit.c:1004 [inline] __se_sys_exit_group kernel/exit.c:1002 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1002 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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 kernel/rcu/tree.c:2980 [inline] call_rcu+0x11a/0x1090 kernel/rcu/tree.c:3054 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x516/0x660 fs/dcache.c:597 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:883 do_unlinkat+0x30c/0x670 fs/namei.c:4088 __do_sys_unlink fs/namei.c:4132 [inline] __se_sys_unlink fs/namei.c:4130 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4130 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88811a4d5dd0 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff88811a4d5dd0, ffff88811a4d5ea0) The buggy address belongs to the page: page:ffffea0004693540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11a4d5 flags: 0x4000000000000200(slab) raw: 4000000000000200 0000000000000000 0000000d00000001 ffff88810018be00 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 4168, ts 170127406459, free_ts 104940711573 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x1a4/0x2d0 mm/slub.c:2965 __d_alloc+0x2d/0x690 fs/dcache.c:1714 d_alloc+0x48/0x260 fs/dcache.c:1793 __lookup_hash+0xcb/0x250 fs/namei.c:1545 filename_create+0x1d7/0x680 fs/namei.c:3658 user_path_create fs/namei.c:3715 [inline] do_symlinkat+0x8b/0x3d0 fs/namei.c:4169 __do_sys_symlinkat fs/namei.c:4190 [inline] __se_sys_symlinkat fs/namei.c:4187 [inline] __x64_sys_symlinkat+0x7b/0x90 fs/namei.c:4187 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5443 [inline] __free_pages+0x146/0x390 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab+0x29/0x40 mm/slub.c:1920 __slab_free+0x313/0x3a0 mm/slub.c:3136 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x15a/0x2d0 mm/slub.c:2965 kmem_cache_zalloc include/linux/slab.h:657 [inline] jbd2_alloc_handle include/linux/jbd2.h:1554 [inline] new_handle fs/jbd2/transaction.c:464 [inline] jbd2__journal_start+0x13d/0x6e0 fs/jbd2/transaction.c:491 __ext4_journal_start_sb+0x242/0x490 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:328 [inline] ext4_dirty_inode+0xb2/0x120 fs/ext4/inode.c:6187 __mark_inode_dirty+0xbb/0x960 fs/fs-writeback.c:2274 Memory state around the buggy address: ffff88811a4d5c80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff88811a4d5d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811a4d5d80: 00 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb ^ ffff88811a4d5e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811a4d5e80: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 10440 at fs/dcache.c:766 fast_dput+0x207/0x290 fs/dcache.c:766 Modules linked in: CPU: 1 PID: 10440 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:766 Code: d9 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 83 d9 f2 ff e9 94 fe ff ff e8 b9 4b b8 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:ffffc90000b17ba0 EFLAGS: 00010293 RAX: ffffffff81ac6b07 RBX: ffff88811a4d5dd0 RCX: ffff88813197bc00 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000b17bc8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000162f64 R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff88811a4d5e28 R15: 1ffff1102349abc5 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd051e69990 CR3: 000000000640f000 CR4: 00000000003506a0 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+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1a1/0x200 fs/incfs/vfs.c:1981 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7c/0x24e0 kernel/exit.c:879 do_group_exit+0x149/0x310 kernel/exit.c:993 __do_sys_exit_group kernel/exit.c:1004 [inline] __se_sys_exit_group kernel/exit.c:1002 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1002 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6f46ede559 Code: Unable to access opcode bytes at RIP 0x7f6f46ede52f. RSP: 002b:00007ffe7cd662d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6f46f74fc3 RCX: 00007f6f46ede559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6f46f74f63 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7cd67590 R13: 00007f6f46f74f63 R14: 00005555727e04e8 R15: 00007ffe7cd68660 ---[ end trace a3795bd3cdbee63a ]--- list_del corruption. prev->next should be ffff88811a4d5c40, but was ffff88811a4d55e0 ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:61! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 10440 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59 Code: 48 89 de e8 76 2e 39 02 0f 0b 48 c7 c7 20 70 40 85 48 89 de e8 65 2e 39 02 0f 0b 48 c7 c7 80 70 40 85 48 89 de e8 54 2e 39 02 <0f> 0b 48 c7 c7 e0 70 40 85 48 89 de e8 43 2e 39 02 0f 0b 00 55 48 RSP: 0018:ffffc90000b17b18 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff88811a4d5c40 RCX: 7886462d5e12c000 RDX: 0000000000000000 RSI: 0000000080000002 RDI: 0000000000000000 RBP: ffffc90000b17b38 R08: ffff8881f7052fff R09: 1ffff1103ee0a5ff R10: dffffc0000000000 R11: ffffed103ee0a600 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88811a4d55e0 R15: ffff88812c2eaf70 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f16f18e12f8 CR3: 000000010d411000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:139 [inline] dentry_unlist fs/dcache.c:526 [inline] __dentry_kill+0x248/0x660 fs/dcache.c:579 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:883 incfs_free_mount_info+0x80/0x200 fs/incfs/data_mgmt.c:167 incfs_kill_sb+0x1a1/0x200 fs/incfs/vfs.c:1981 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x44f/0x500 fs/namespace.c:1123 __cleanup_mnt+0x19/0x20 fs/namespace.c:1130 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7c/0x24e0 kernel/exit.c:879 do_group_exit+0x149/0x310 kernel/exit.c:993 __do_sys_exit_group kernel/exit.c:1004 [inline] __se_sys_exit_group kernel/exit.c:1002 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1002 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6f46ede559 Code: Unable to access opcode bytes at RIP 0x7f6f46ede52f. RSP: 002b:00007ffe7cd662d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6f46f74fc3 RCX: 00007f6f46ede559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f6f46f74f63 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe7cd67590 R13: 00007f6f46f74f63 R14: 00005555727e04e8 R15: 00007ffe7cd68660 Modules linked in: ---[ end trace a3795bd3cdbee63b ]--- RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59 Code: 48 89 de e8 76 2e 39 02 0f 0b 48 c7 c7 20 70 40 85 48 89 de e8 65 2e 39 02 0f 0b 48 c7 c7 80 70 40 85 48 89 de e8 54 2e 39 02 <0f> 0b 48 c7 c7 e0 70 40 85 48 89 de e8 43 2e 39 02 0f 0b 00 55 48 RSP: 0018:ffffc90000b17b18 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff88811a4d5c40 RCX: 7886462d5e12c000 RDX: 0000000000000000 RSI: 0000000080000002 RDI: 0000000000000000 RBP: ffffc90000b17b38 R08: ffff8881f7052fff R09: 1ffff1103ee0a5ff R10: dffffc0000000000 R11: ffffed103ee0a600 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88811a4d55e0 R15: ffff88812c2eaf70 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f16f18e12f8 CR3: 000000010d411000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400