================================================================== BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:381 [inline] BUG: KASAN: slab-use-after-free in locks_remove_posix+0x10f/0x630 fs/locks.c:2667 Read of size 8 at addr ffff88803122d680 by task syz.0.437/7831 CPU: 0 UID: 0 PID: 7831 Comm: syz.0.437 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 list_empty include/linux/list.h:381 [inline] locks_remove_posix+0x10f/0x630 fs/locks.c:2667 filp_flush+0x113/0x190 fs/open.c:1537 filp_close+0x1d/0x40 fs/open.c:1546 close_files fs/file.c:494 [inline] put_files_struct+0x1ba/0x350 fs/file.c:509 do_exit+0x67f/0x2310 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff5aef8f749 Code: Unable to access opcode bytes at 0x7ff5aef8f71f. RSP: 002b:00007ff5afeca0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ff5af1e5fa8 RCX: 00007ff5aef8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ff5af1e5fa8 RBP: 00007ff5af1e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff5af1e6038 R14: 00007ffe10521c80 R15: 00007ffe10521d68 Allocated by task 7833: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5265 locks_get_lock_context+0x134/0x3b0 fs/locks.c:186 generic_add_lease fs/locks.c:1811 [inline] generic_setlease+0x528/0x1280 fs/locks.c:1970 do_fcntl_add_lease+0x34d/0x460 fs/locks.c:2073 fcntl_setlease+0x123/0x180 fs/locks.c:2098 do_fcntl+0x867/0x1a50 fs/fcntl.c:535 __do_sys_fcntl fs/fcntl.c:602 [inline] __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7830: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6774 __destroy_inode+0x2ea/0x670 fs/inode.c:373 destroy_inode fs/inode.c:394 [inline] evict+0x87d/0xae0 fs/inode.c:861 __dentry_kill+0x209/0x660 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803122d630 which belongs to the cache file_lock_ctx of size 112 The buggy address is located 80 bytes inside of freed 112-byte region [ffff88803122d630, ffff88803122d6a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803122d580 pfn:0x3122d flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88814047c640 dead000000000122 0000000000000000 raw: ffff88803122d580 0000000080170015 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5206, tgid 5206 (udevd), ts 45365449212, free_ts 45357729534 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf2b/0x1960 mm/slub.c:4651 __slab_alloc+0x65/0x100 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] kmem_cache_alloc_noprof+0x40f/0x710 mm/slub.c:5265 locks_get_lock_context+0x134/0x3b0 fs/locks.c:186 flock_lock_inode+0xf2/0x1410 fs/locks.c:1083 flock_lock_inode_wait fs/locks.c:2134 [inline] locks_lock_inode_wait+0x107/0x410 fs/locks.c:2161 locks_lock_file_wait include/linux/filelock.h:446 [inline] __do_sys_flock fs/locks.c:2229 [inline] __se_sys_flock+0x467/0x5b0 fs/locks.c:2185 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 932 tgid 932 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 Memory state around the buggy address: ffff88803122d580: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff88803122d600: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb >ffff88803122d680: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88803122d700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88803122d780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================