================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:678 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x801/0x1350 kernel/locking/mutex.c:760 Read of size 8 at addr ffff888029d700a0 by task syz.2.1302/15327 CPU: 0 UID: 0 PID: 15327 Comm: syz.2.1302 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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 __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x801/0x1350 kernel/locking/mutex.c:760 l2cap_register_user+0x67/0x200 net/bluetooth/l2cap_core.c:1698 hidp_connection_add+0x1599/0x1a50 net/bluetooth/hidp/core.c:1378 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:81 [inline] hidp_sock_ioctl+0x36c/0x560 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0xdc/0x300 net/socket.c:1238 sock_ioctl+0x576/0x790 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b23f8ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5b24d7c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5b241c6090 RCX: 00007f5b23f8ebe9 RDX: 0000200000000340 RSI: 00000000400448c8 RDI: 0000000000000005 RBP: 00007f5b24011e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5b241c6128 R14: 00007f5b241c6090 R15: 00007ffdd36ecc38 Allocated by task 13937: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:5366 [inline] __kmalloc_noprof+0x411/0x7f0 mm/slub.c:5378 kmalloc_noprof include/linux/slab.h:960 [inline] kzalloc_noprof include/linux/slab.h:1090 [inline] hci_alloc_dev_priv+0x28/0x2060 net/bluetooth/hci_core.c:2448 hci_alloc_dev include/net/bluetooth/hci_core.h:1729 [inline] __vhci_create_device drivers/bluetooth/hci_vhci.c:421 [inline] vhci_create_device+0x120/0x650 drivers/bluetooth/hci_vhci.c:479 vhci_get_user drivers/bluetooth/hci_vhci.c:536 [inline] vhci_write+0x3ce/0x4a0 drivers/bluetooth/hci_vhci.c:616 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15304: 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2484 [inline] slab_free mm/slub.c:6121 [inline] kfree+0x199/0x6d0 mm/slub.c:6329 bt_host_release+0x82/0x90 net/bluetooth/hci_sysfs.c:87 device_release+0x99/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x228/0x480 lib/kobject.c:737 vhci_release+0x15a/0x1a0 drivers/bluetooth/hci_vhci.c:691 __fput+0x449/0xa70 fs/file_table.c:468 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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:559 insert_work+0x3d/0x330 kernel/workqueue.c:2186 __queue_work+0xbaf/0xfb0 kernel/workqueue.c:2345 queue_work_on+0x181/0x270 kernel/workqueue.c:2392 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Second to 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:559 insert_work+0x3d/0x330 kernel/workqueue.c:2186 __queue_work+0xcd2/0xfb0 kernel/workqueue.c:2341 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1793 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x646/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 The buggy address belongs to the object at ffff888029d70000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 160 bytes inside of freed 8192-byte region [ffff888029d70000, ffff888029d72000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29d70 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a842280 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a842280 0000000000000000 dead000000000001 head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000a75c01 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 0x528c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP), pid 7889, tgid 7889 (syz-executor), ts 232401019934, free_ts 232391931842 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3863 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5153 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2996 [inline] allocate_slab+0x8a/0x330 mm/slub.c:3164 new_slab mm/slub.c:3218 [inline] ___slab_alloc+0xbd1/0x13f0 mm/slub.c:4420 __slab_alloc+0x55/0xa0 mm/slub.c:4511 __slab_alloc_node mm/slub.c:4586 [inline] slab_alloc_node mm/slub.c:4996 [inline] __do_kmalloc_node mm/slub.c:5365 [inline] __kvmalloc_node_noprof+0x6ba/0x910 mm/slub.c:6527 kvmalloc_array_node_noprof include/linux/slab.h:1118 [inline] __ptr_ring_init_queue_alloc_noprof include/linux/ptr_ring.h:471 [inline] ptr_ring_init_noprof include/linux/ptr_ring.h:489 [inline] wg_packet_queue_init+0xbc/0x320 drivers/net/wireguard/queueing.c:32 wg_newlink+0x326/0x640 drivers/net/wireguard/device.c:355 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3825 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 page last free pid 7995 tgid 7994 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2900 discard_slab mm/slub.c:3262 [inline] __put_partials+0x146/0x170 mm/slub.c:3727 put_cpu_partial+0x17c/0x250 mm/slub.c:3802 __slab_free+0x2b9/0x390 mm/slub.c:5555 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4710 [inline] slab_alloc_node mm/slub.c:5008 [inline] __do_kmalloc_node mm/slub.c:5365 [inline] __kmalloc_node_track_caller_noprof+0x519/0x800 mm/slub.c:5385 __do_krealloc mm/slub.c:6406 [inline] krealloc_node_align_noprof+0x140/0x390 mm/slub.c:6465 bch2_sb_realloc+0x353/0x640 fs/bcachefs/super-io.c:222 read_one_super+0x3a3/0x850 fs/bcachefs/super-io.c:759 __bch2_read_super+0x6c6/0x1040 fs/bcachefs/super-io.c:851 bch2_fs_open+0x1fe/0x2600 fs/bcachefs/super.c:2401 bch2_fs_get_tree+0x44f/0x1520 fs/bcachefs/fs.c:2472 vfs_get_tree+0x8f/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1274 [inline] do_new_mount_fc fs/namespace.c:3726 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3802 Memory state around the buggy address: ffff888029d6ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029d70000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888029d70080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029d70100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029d70180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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