================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 Read of size 1 at addr ffff888062cf5728 by task syz-executor/5826 CPU: 1 UID: 0 PID: 5826 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1426 shrink_dentry_list+0x2e3/0x5e0 fs/dcache.c:1222 shrink_dcache_tree+0xe9/0x5d0 fs/dcache.c:-1 shrink_dcache_parent fs/dcache.c:1693 [inline] d_invalidate+0xde/0x210 fs/dcache.c:1775 proc_invalidate_siblings_dcache+0x3d3/0x6c0 fs/proc/inode.c:142 release_task+0x1207/0x16f0 kernel/exit.c:291 wait_task_zombie kernel/exit.c:1279 [inline] wait_consider_task+0x1966/0x2e30 kernel/exit.c:1506 do_wait_thread kernel/exit.c:1569 [inline] __do_wait+0x155/0x740 kernel/exit.c:1687 do_wait+0x1e7/0x510 kernel/exit.c:1721 kernel_wait4+0x232/0x2b0 kernel/exit.c:1880 __do_sys_wait4 kernel/exit.c:1908 [inline] __se_sys_wait4 kernel/exit.c:1904 [inline] __x64_sys_wait4+0x166/0x240 kernel/exit.c:1904 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66bcc0d04e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffda963f528 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 0000555578eaa500 RCX: 00007f66bcc0d04e RDX: 0000000040000001 RSI: 00007ffda963f5cc RDI: ffffffffffffffff RBP: 00007ffda963f5cc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388 R13: 00000000000927c0 R14: 0000000000028a58 R15: 00007ffda963f620 Allocated by task 6636: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_lru_noprof+0x33c/0x680 mm/slub.c:4917 __d_alloc+0x37/0x6f0 fs/dcache.c:1807 d_alloc_parallel+0xe6/0x1610 fs/dcache.c:2671 __lookup_slow+0x152/0x440 fs/namei.c:1900 lookup_slow+0x53/0x70 fs/namei.c:1932 walk_component fs/namei.c:2278 [inline] link_path_walk+0x1273/0x18d0 fs/namei.c:2649 path_openat+0x2d5/0x38a0 fs/namei.c:4854 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 29: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6373 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 __dentry_kill+0x4a9/0x690 fs/dcache.c:737 finish_dput+0xc9/0x480 fs/dcache.c:927 proc_invalidate_siblings_dcache+0x3db/0x6c0 fs/proc/inode.c:143 release_task+0x1207/0x16f0 kernel/exit.c:291 exit_notify kernel/exit.c:776 [inline] do_exit+0x1674/0x22c0 kernel/exit.c:987 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888062cf5658 which belongs to the cache dentry of size 376 The buggy address is located 208 bytes inside of freed 376-byte region [ffff888062cf5658, ffff888062cf57d0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x62cf4 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888062cf5ef1 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88801baf53c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800120012 00000000f5000000 ffff888062cf5ef1 head: 0080000000000040 ffff88801baf53c0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800120012 00000000f5000000 ffff888062cf5ef1 head: 0080000000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5195, tgid 5195 (udevd), ts 107525613012, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27d6/0x2850 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] kmem_cache_alloc_lru_noprof+0x433/0x680 mm/slub.c:4917 __d_alloc+0x37/0x6f0 fs/dcache.c:1807 d_alloc_parallel+0xe6/0x1610 fs/dcache.c:2671 lookup_open fs/namei.c:4426 [inline] open_last_lookups fs/namei.c:4611 [inline] path_openat+0xcc3/0x38a0 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page_owner free stack trace missing Memory state around the buggy address: ffff888062cf5600: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb ffff888062cf5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062cf5700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888062cf5780: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc ffff888062cf5800: fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================