================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:750 Read of size 4 at addr ffff88811a495990 by task syz-executor/410 CPU: 0 PID: 410 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 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+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 fast_dput+0x1e9/0x290 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+0x1aa/0x210 fs/incfs/vfs.c:1979 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1114 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 __do_sys_exit_group kernel/exit.c:997 [inline] __se_sys_exit_group kernel/exit.c:995 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8b5c9b1ec9 Code: Unable to access opcode bytes at RIP 0x7f8b5c9b1e9f. RSP: 002b:00007fff006a81a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f8b5ca34ddd RCX: 00007f8b5c9b1ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 00007fff006a5f47 R09: 00007fff006a9460 R10: 0000000000000009 R11: 0000000000000246 R12: 00007fff006a9460 R13: 00007f8b5ca34d7d R14: 00005555723b74a8 R15: 00007fff006aa530 Allocated by task 811: 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+0xbd/0xf0 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+0x165/0x2e0 mm/slub.c:2965 __d_alloc+0x2d/0x6a0 fs/dcache.c:1714 d_alloc fs/dcache.c:1793 [inline] d_alloc_parallel+0xd6/0x1320 fs/dcache.c:2547 __lookup_slow+0x13e/0x3e0 fs/namei.c:1625 lookup_one_len+0x18e/0x2c0 fs/namei.c:2656 incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210 open_or_create_special_dir+0x4f/0x1d0 fs/incfs/vfs.c:469 incfs_mount_fs+0x434/0x8c0 fs/incfs/vfs.c:1867 legacy_get_tree+0xed/0x190 fs/fs_context.c:593 vfs_get_tree+0x89/0x260 fs/super.c:1572 do_new_mount+0x25a/0xa20 fs/namespace.c:2997 path_mount+0x572/0xc80 fs/namespace.c:3327 do_mount fs/namespace.c:3340 [inline] __do_sys_mount fs/namespace.c:3548 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3525 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3525 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 275: 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+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 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+0x10e/0x1050 kernel/rcu/tree.c:3054 dentry_free+0xbd/0x150 fs/dcache.c:-1 __dentry_kill+0x50a/0x650 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+0x1aa/0x210 fs/incfs/vfs.c:1979 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1114 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 __do_sys_exit_group kernel/exit.c:997 [inline] __se_sys_exit_group kernel/exit.c:995 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995 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 ffff88811a495990 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff88811a495990, ffff88811a495a60) The buggy address belongs to the page: page:ffffea0004692540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11a495 flags: 0x4000000000000200(slab) raw: 4000000000000200 dead000000000100 dead000000000122 ffff88810018bb00 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 279, ts 25448802947, 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+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 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+0x2a6/0x450 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+0x1af/0x2e0 mm/slub.c:2965 __d_alloc+0x2d/0x6a0 fs/dcache.c:1714 d_alloc_pseudo+0x1d/0x70 fs/dcache.c:1843 alloc_file_pseudo+0xc8/0x1f0 fs/file_table.c:226 sock_alloc_file+0xba/0x260 net/socket.c:412 sock_map_fd net/socket.c:436 [inline] __sys_socket+0x12b/0x190 net/socket.c:1533 __do_sys_socket net/socket.c:1538 [inline] __se_sys_socket net/socket.c:1536 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1536 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb page_owner free stack trace missing Memory state around the buggy address: ffff88811a495880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811a495900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc >ffff88811a495980: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811a495a00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88811a495a80: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 0 PID: 410 at fs/dcache.c:766 fast_dput+0x210/0x290 fs/dcache.c:766 Modules linked in: CPU: 0 PID: 410 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:766 Code: 04 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 3a 04 f3 ff e9 8c fe ff ff e8 90 14 b9 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:ffffc90000cf7b80 EFLAGS: 00010293 RAX: ffffffff81aa9110 RBX: ffff88811a495990 RCX: ffff8881213ee2c0 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000cf7bb0 R08: 0000000000000004 R09: 0000000000000003 R10: fffff5200019ef60 R11: 1ffff9200019ef60 R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff88811a4959e8 R15: 1ffff11023492b3d FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc52332571a CR3: 000000010cb39000 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+0x60/0x200 fs/incfs/data_mgmt.c:166 incfs_kill_sb+0x1aa/0x210 fs/incfs/vfs.c:1979 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1114 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 __do_sys_exit_group kernel/exit.c:997 [inline] __se_sys_exit_group kernel/exit.c:995 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8b5c9b1ec9 Code: Unable to access opcode bytes at RIP 0x7f8b5c9b1e9f. RSP: 002b:00007fff006a81a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f8b5ca34ddd RCX: 00007f8b5c9b1ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 00007fff006a5f47 R09: 00007fff006a9460 R10: 0000000000000009 R11: 0000000000000246 R12: 00007fff006a9460 R13: 00007f8b5ca34d7d R14: 00005555723b74a8 R15: 00007fff006aa530 ---[ end trace 47c7523139a253fd ]--- list_del corruption. prev->next should be ffff88811a495e60, but was ffff88811a495800 ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:61! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 410 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59 Code: 48 89 de e8 c6 18 32 02 0f 0b 48 c7 c7 a0 29 20 85 48 89 de e8 b5 18 32 02 0f 0b 48 c7 c7 00 2a 20 85 48 89 de e8 a4 18 32 02 <0f> 0b 48 c7 c7 60 2a 20 85 48 89 de e8 93 18 32 02 0f 0b 00 55 48 RSP: 0018:ffffc90000cf7af8 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff88811a495e60 RCX: f7587ed2c5dfa800 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc90000cf7b18 R08: dffffc0000000000 R09: ffffed103ee2a5f8 R10: ffffed103ee2a5f8 R11: 1ffff1103ee2a5f7 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88811a495800 R15: ffff88811a45ce70 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44f86cc710 CR3: 000000011d245000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry include/linux/list.h:132 [inline] dentry_unlist fs/dcache.c:526 [inline] __dentry_kill+0x24c/0x650 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+0x1aa/0x210 fs/incfs/vfs.c:1979 deactivate_locked_super+0xa0/0x100 fs/super.c:335 deactivate_super+0xaf/0xe0 fs/super.c:366 cleanup_mnt+0x446/0x500 fs/namespace.c:1114 __cleanup_mnt+0x19/0x20 fs/namespace.c:1121 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 __do_sys_exit_group kernel/exit.c:997 [inline] __se_sys_exit_group kernel/exit.c:995 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8b5c9b1ec9 Code: Unable to access opcode bytes at RIP 0x7f8b5c9b1e9f. RSP: 002b:00007fff006a81a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f8b5ca34ddd RCX: 00007f8b5c9b1ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 00007fff006a5f47 R09: 00007fff006a9460 R10: 0000000000000009 R11: 0000000000000246 R12: 00007fff006a9460 R13: 00007f8b5ca34d7d R14: 00005555723b74a8 R15: 00007fff006aa530 Modules linked in: ---[ end trace 47c7523139a253fe ]--- RIP: 0010:__list_del_entry_valid+0x10c/0x120 lib/list_debug.c:59 Code: 48 89 de e8 c6 18 32 02 0f 0b 48 c7 c7 a0 29 20 85 48 89 de e8 b5 18 32 02 0f 0b 48 c7 c7 00 2a 20 85 48 89 de e8 a4 18 32 02 <0f> 0b 48 c7 c7 60 2a 20 85 48 89 de e8 93 18 32 02 0f 0b 00 55 48 RSP: 0018:ffffc90000cf7af8 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff88811a495e60 RCX: f7587ed2c5dfa800 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc90000cf7b18 R08: dffffc0000000000 R09: ffffed103ee2a5f8 R10: ffffed103ee2a5f8 R11: 1ffff1103ee2a5f7 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff88811a495800 R15: ffff88811a45ce70 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44f86cc710 CR3: 000000011d245000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400