================================================================== 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 ffff88803e894440 by task syz.3.209/6555 CPU: 0 UID: 0 PID: 6555 Comm: syz.3.209 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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/0xa20 kernel/locking/rtmutex.c:1430 spin_unlock include/linux/spinlock_rt.h:109 [inline] d_alloc_parallel+0x10c0/0x16c0 fs/dcache.c:2826 lookup_open fs/namei.c:4423 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0xbf0/0x3850 fs/namei.c:4856 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd4db08d68e 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:00007fd4d931db28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd4d931e6c0 RCX: 00007fd4db08d68e RDX: 0000000000000002 RSI: 00007fd4d931dc00 RDI: ffffffffffffff9c RBP: 00007fd4db162d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd4db346038 R14: 00007fd4db345fa0 R15: 00007ffd70b50f78 Allocated by task 6556: 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:4610 [inline] slab_alloc_node mm/slub.c:4943 [inline] kmem_cache_alloc_lru_noprof+0x347/0x6a0 mm/slub.c:4976 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc_parallel+0xde/0x16c0 fs/dcache.c:2761 lookup_open fs/namei.c:4423 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0xbf0/0x3850 fs/namei.c:4856 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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+0x40/0x50 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:2703 [inline] slab_free mm/slub.c:6402 [inline] kmem_cache_free+0x187/0x6c0 mm/slub.c:6529 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core kernel/rcu/tree.c:2897 [inline] rcu_cpu_kthread+0x950/0x1480 kernel/rcu/tree.c:2985 smpboot_thread_fn+0x57c/0xa80 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:3159 [inline] call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279 dentry_kill+0x4d3/0x880 fs/dcache.c:845 finish_dput+0x1a/0x260 fs/dcache.c:1001 handle_mounts fs/namei.c:1753 [inline] step_into_slowpath+0x4cc/0x820 fs/namei.c:2104 step_into fs/namei.c:2152 [inline] open_last_lookups fs/namei.c:4643 [inline] path_openat+0x226a/0x3850 fs/namei.c:4856 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803e894370 which belongs to the cache dentry of size 376 The buggy address is located 208 bytes inside of freed 376-byte region [ffff88803e894370, ffff88803e8944e8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3e894 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88803540ed01 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88801be88500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800120012 00000000f5000000 ffff88803540ed01 head: 0080000000000040 ffff88801be88500 dead000000000100 dead000000000122 head: 0000000000000000 0000000800120012 00000000f5000000 ffff88803540ed01 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 4980, tgid 4980 (udevd), ts 52090113336, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x2639/0x26b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3406 new_slab mm/slub.c:3452 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7335 refill_sheaf mm/slub.c:2830 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4701 alloc_from_pcs mm/slub.c:4799 [inline] slab_alloc_node mm/slub.c:4931 [inline] kmem_cache_alloc_lru_noprof+0x45e/0x6a0 mm/slub.c:4976 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc+0x4b/0x190 fs/dcache.c:1981 lookup_one_qstr_excl+0xd8/0x360 fs/namei.c:1806 __start_dirop fs/namei.c:2920 [inline] start_dirop fs/namei.c:2942 [inline] filename_create+0x20e/0x370 fs/namei.c:4951 filename_symlinkat+0xf7/0x420 fs/namei.c:5675 __do_sys_symlink fs/namei.c:5708 [inline] __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5704 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 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: ffff88803e894300: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb ffff88803e894380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803e894400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803e894480: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88803e894500: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00 ==================================================================