RBP: 00007ffea1a28990 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffea1a29a20 R13: 00007f8fccf81d7d R14: 00000000000259d1 R15: 00007ffea1a29a60 ---[ end trace 6fa3f0a649064fb4 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:750 Read of size 4 at addr ffff88811072d660 by task syz-executor/3460 CPU: 1 PID: 3460 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8fccf002f7 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffea1a288d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8fccf002f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffea1a28990 RBP: 00007ffea1a28990 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffea1a29a20 R13: 00007f8fccf81d7d R14: 00000000000259d1 R15: 00007ffea1a29a60 Allocated by task 3531: 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 7: 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 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+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 do_unlinkat+0x304/0x670 fs/namei.c:4038 __do_sys_unlink fs/namei.c:4082 [inline] __se_sys_unlink fs/namei.c:4080 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4080 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 ffff88811072d660 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff88811072d660, ffff88811072d730) The buggy address belongs to the page: page:ffffea000441cb40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811072d880 pfn:0x11072d flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea0004b2b988 ffffea0004b2cdc8 ffff88810018b080 raw: ffff88811072d880 00000000000f000e 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 109, ts 4813358668, 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+0x4b/0x1d0 fs/dcache.c:1793 __lookup_hash+0xcb/0x250 fs/namei.c:1537 do_renameat2+0x4b7/0xe60 fs/namei.c:4579 __do_sys_rename fs/namei.c:4670 [inline] __se_sys_rename fs/namei.c:4668 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:4668 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: ffff88811072d500: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 ffff88811072d580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811072d600: 00 00 00 00 fc fc fc fc fc fc fc fc fa fb fb fb ^ ffff88811072d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811072d700: fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 3460 at fs/dcache.c:766 fast_dput+0x210/0x290 fs/dcache.c:766 Modules linked in: CPU: 1 PID: 3460 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:ffffc90000db7ce8 EFLAGS: 00010293 RAX: ffffffff81aa9110 RBX: ffff88811072d660 RCX: ffff888136d5a780 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000db7d18 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520001b6f8c R11: 1ffff920001b6f8c R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff88811072d6b8 R15: 1ffff110220e5ad7 FS: 000055555d6fc500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc65963b130 CR3: 0000000136c96000 CR4: 00000000003526a0 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8fccf002f7 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 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 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffea1a288d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8fccf002f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffea1a28990 RBP: 00007ffea1a28990 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffea1a29a20 R13: 00007f8fccf81d7d R14: 00000000000259d1 R15: 00007ffea1a29a60 ---[ end trace 6fa3f0a649064fb5 ]--- ------------[ cut here ]------------ WARNING: CPU: 1 PID: 3460 at fs/inode.c:304 drop_nlink+0xc5/0x110 fs/inode.c:304 Modules linked in: CPU: 0 PID: 3460 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:304 Code: 1b 48 8d bb b8 04 00 00 be 08 00 00 00 e8 93 22 f2 ff f0 48 ff 83 b8 04 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 bb 30 b8 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:ffffc90000db7d70 EFLAGS: 00010293 RAX: ffffffff81ab74e5 RBX: ffff8881130c2840 RCX: ffff888136d5a780 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000db7d98 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520001b6f9c R11: 1ffff920001b6f9c R12: dffffc0000000000 R13: 1ffff11022618511 R14: ffff8881130c2888 R15: 0000000000000000 FS: 000055555d6fc500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e423ffc CR3: 0000000136c96000 CR4: 00000000003526a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: shmem_rmdir+0x5b/0x90 mm/shmem.c:3011 vfs_rmdir+0x1b3/0x3e0 fs/namei.c:3852 do_rmdir+0x218/0x620 fs/namei.c:3912 __do_sys_unlinkat fs/namei.c:4076 [inline] __se_sys_unlinkat fs/namei.c:4070 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8fccefe5a7 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffea1a288d8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f8fccefe5a7 RDX: 0000000000000200 RSI: 00007ffea1a29a20 RDI: 00000000ffffff9c RBP: 00007f8fccf81d7d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffea1a29a20 R13: 00007f8fccf81d7d R14: 00000000000259d1 R15: 00007ffea1a29a60 ---[ end trace 6fa3f0a649064fb6 ]---