RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f92c3cef45c R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff299e6010 R13: 00007f92c3cef45c R14: 00005555570e74e8 R15: 00007fff299e70e0 ---[ end trace 058062928a3b2fe3 ]--- ================================================================== BUG: KASAN: use-after-free in fast_dput+0x1e0/0x290 fs/dcache.c:750 Read of size 4 at addr ffff8881107da110 by task syz-executor/1035 CPU: 0 PID: 1035 Comm: syz-executor Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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:1979 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:873 do_group_exit+0x149/0x310 kernel/exit.c:987 __do_sys_exit_group kernel/exit.c:998 [inline] __se_sys_exit_group kernel/exit.c:996 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:996 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f92c3c59019 Code: Unable to access opcode bytes at RIP 0x7f92c3c58fef. RSP: 002b:00007fff299e4d58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f92c3cef4bc RCX: 00007f92c3c59019 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f92c3cef45c R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff299e6010 R13: 00007f92c3cef45c R14: 00005555570e74e8 R15: 00007fff299e70e0 Allocated by task 1638: 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:2664 incfs_lookup_dentry+0x60/0xb0 fs/incfs/data_mgmt.c:210 open_or_create_special_dir+0x4c/0x1e0 fs/incfs/vfs.c:469 incfs_mount_fs+0x434/0x8d0 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/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 1674: 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:1979 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:873 do_group_exit+0x149/0x310 kernel/exit.c:987 __do_sys_exit_group kernel/exit.c:998 [inline] __se_sys_exit_group kernel/exit.c:996 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:996 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 shrink_dentry_list+0x38e/0x500 fs/dcache.c:1146 shrink_dcache_parent+0xa9/0x270 fs/dcache.c:-1 d_invalidate+0x112/0x2d0 fs/dcache.c:1682 proc_invalidate_siblings_dcache+0x298/0x3c0 fs/proc/inode.c:150 proc_flush_pid+0x1d/0x20 fs/proc/base.c:3428 release_task+0x10bc/0x1200 kernel/exit.c:270 wait_task_zombie kernel/exit.c:1172 [inline] wait_consider_task+0x182f/0x2810 kernel/exit.c:1399 do_wait_thread kernel/exit.c:1462 [inline] do_wait+0x22b/0x6a0 kernel/exit.c:1533 kernel_wait4+0x1d1/0x2b0 kernel/exit.c:1695 __do_sys_wait4 kernel/exit.c:1723 [inline] __se_sys_wait4 kernel/exit.c:1719 [inline] __x64_sys_wait4+0x163/0x230 kernel/exit.c:1719 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 ffff8881107da110 which belongs to the cache dentry of size 208 The buggy address is located 0 bytes inside of 208-byte region [ffff8881107da110, ffff8881107da1e0) The buggy address belongs to the page: page:ffffea000441f680 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881107daee0 pfn:0x1107da flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea00046d7240 0000000200000002 ffff88810018a780 raw: ffff8881107daee0 00000000800f000e 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 171, ts 7166574054, 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+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_anon fs/dcache.c:1814 [inline] d_alloc_cursor+0x41/0xd0 fs/dcache.c:1820 dcache_dir_open+0x3b/0x80 fs/libfs.c:81 do_dentry_open+0x7a5/0x10a0 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:944 do_open fs/namei.c:3399 [inline] path_openat+0x26c3/0x3040 fs/namei.c:3517 do_filp_open+0x1df/0x400 fs/namei.c:3544 do_sys_openat2+0x19f/0x750 fs/open.c:1219 do_sys_open fs/open.c:1235 [inline] __do_sys_openat fs/open.c:1251 [inline] __se_sys_openat fs/open.c:1246 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1246 page_owner free stack trace missing Memory state around the buggy address: ffff8881107da000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881107da080: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc >ffff8881107da100: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881107da180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8881107da200: fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1035 at fs/dcache.c:766 fast_dput+0x207/0x290 fs/dcache.c:766 Modules linked in: CPU: 1 PID: 1035 Comm: syz-executor Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:fast_dput+0x207/0x290 fs/dcache.c:766 Code: e0 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 e0 f2 ff e9 94 fe ff ff e8 79 6b 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:ffffc90000b27ba0 EFLAGS: 00010293 RAX: ffffffff81ac3807 RBX: ffff8881107da110 RCX: ffff88810fcb2780 RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001 RBP: ffffc90000b27bc8 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000164f64 R12: 00000000ffffff80 R13: dffffc0000000000 R14: ffff8881107da168 R15: 1ffff110220fb42d FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd0cfe3c70 CR3: 000000012583d000 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:1979 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:873 do_group_exit+0x149/0x310 kernel/exit.c:987 __do_sys_exit_group kernel/exit.c:998 [inline] __se_sys_exit_group kernel/exit.c:996 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:996 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f92c3c59019 Code: Unable to access opcode bytes at RIP 0x7f92c3c58fef. RSP: 002b:00007fff299e4d58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f92c3cef4bc RCX: 00007f92c3c59019 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000009 R08: 0000000000000000 R09: 00007f92c3cef45c R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff299e6010 R13: 00007f92c3cef45c R14: 00005555570e74e8 R15: 00007fff299e70e0 ---[ end trace 058062928a3b2fe4 ]---