================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 Read of size 1 at addr ffff8880330c9458 by task syz.4.224/6965 CPU: 1 UID: 0 PID: 6965 Comm: syz.4.224 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 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:573 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] mqueue_flush_file+0x49/0x270 ipc/mqueue.c:663 filp_flush+0xbd/0x190 fs/open.c:1533 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: 0033:0x7f9f8c18f749 Code: Unable to access opcode bytes at 0x7f9f8c18f71f. RSP: 002b:00007f9f8cfef0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 00007f9f8c3e6098 RCX: 00007f9f8c18f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9f8c3e6098 RBP: 00007f9f8c3e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9f8c3e6128 R14: 00007ffef7c6c900 R15: 00007ffef7c6c9e8 Allocated by task 6964: 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_lru_noprof+0x36c/0x6e0 mm/slub.c:5277 mqueue_alloc_inode+0x28/0x40 ipc/mqueue.c:502 alloc_inode+0x6a/0x1b0 fs/inode.c:346 new_inode+0x22/0x170 fs/inode.c:1175 mqueue_get_inode+0x27/0xb50 ipc/mqueue.c:297 mqueue_create_attr+0x1ac/0x2e0 ipc/mqueue.c:590 vfs_mkobj+0xcf/0x290 fs/namei.c:4153 prepare_open ipc/mqueue.c:876 [inline] mqueue_file_open ipc/mqueue.c:905 [inline] do_mq_open+0x60d/0x7c0 ipc/mqueue.c:928 __do_sys_mq_open ipc/mqueue.c:941 [inline] __se_sys_mq_open ipc/mqueue.c:934 [inline] __x64_sys_mq_open+0x16a/0x1c0 ipc/mqueue.c:934 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 23: 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 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 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1067 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239 destroy_inode fs/inode.c:401 [inline] evict+0x931/0xae0 fs/inode.c:861 __do_sys_mq_unlink ipc/mqueue.c:972 [inline] __se_sys_mq_unlink+0x2c5/0x360 ipc/mqueue.c:944 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 The buggy address belongs to the object at ffff8880330c9440 which belongs to the cache mqueue_inode_cache of size 1576 The buggy address is located 24 bytes inside of freed 1576-byte region [ffff8880330c9440, ffff8880330c9a68) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880330c8d80 pfn:0x330c8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888078f94e01 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88814629f8c0 dead000000000122 0000000000000000 raw: ffff8880330c8d80 0000000080120010 00000000f5000000 ffff888078f94e01 head: 00fff00000000040 ffff88814629f8c0 dead000000000122 0000000000000000 head: ffff8880330c8d80 0000000080120010 00000000f5000000 ffff888078f94e01 head: 00fff00000000003 ffffea0000cc3201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5839, tgid 5839 (syz-executor), ts 74089964696, free_ts 74086428615 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_lru_noprof+0x3fe/0x6e0 mm/slub.c:5277 mqueue_alloc_inode+0x28/0x40 ipc/mqueue.c:502 alloc_inode+0x6a/0x1b0 fs/inode.c:346 new_inode+0x22/0x170 fs/inode.c:1175 mqueue_get_inode ipc/mqueue.c:297 [inline] mqueue_fill_super+0xdc/0x380 ipc/mqueue.c:416 vfs_get_super fs/super.c:1324 [inline] get_tree_nodev+0xbb/0x150 fs/super.c:1343 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1209 [inline] fc_mount_longterm+0x1c/0x100 fs/namespace.c:1220 mq_create_mount ipc/mqueue.c:486 [inline] mq_init_ns+0x275/0x360 ipc/mqueue.c:1639 page last free pid 5490 tgid 5490 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 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1428 netlink_recvmsg+0x5b2/0xa30 net/netlink/af_netlink.c:1972 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1084 ____sys_recvmsg+0x21e/0x4c0 net/socket.c:-1 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2863 __sys_recvmsg net/socket.c:2896 [inline] __do_sys_recvmsg net/socket.c:2902 [inline] __se_sys_recvmsg net/socket.c:2899 [inline] __x64_sys_recvmsg+0x198/0x260 net/socket.c:2899 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 Memory state around the buggy address: ffff8880330c9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880330c9380: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc >ffff8880330c9400: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff8880330c9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880330c9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================