================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common+0xc85/0x2390 kernel/locking/mutex.c:671 Read of size 8 at addr ffff888025388060 by task khidpd_10000008/4970 CPU: 0 PID: 4970 Comm: khidpd_10000008 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] __mutex_lock_common+0xc85/0x2390 kernel/locking/mutex.c:671 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 l2cap_unregister_user+0x66/0x1a0 net/bluetooth/l2cap_core.c:1870 hidp_session_thread+0x3c4/0x400 net/bluetooth/hidp/core.c:1305 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4194: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] hci_alloc_dev_priv+0x23/0x1d20 net/bluetooth/hci_core.c:3775 hci_alloc_dev include/net/bluetooth/hci_core.h:1242 [inline] __vhci_create_device drivers/bluetooth/hci_vhci.c:102 [inline] vhci_create_device+0x122/0x5c0 drivers/bluetooth/hci_vhci.c:153 vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline] vhci_write+0x391/0x450 drivers/bluetooth/hci_vhci.c:290 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 6094: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 hci_release_dev+0x1378/0x14e0 net/bluetooth/hci_core.c:4096 bt_host_release+0x7e/0x90 net/bluetooth/hci_sysfs.c:85 device_release+0x92/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:713 [inline] kobject_release lib/kobject.c:744 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x21d/0x460 lib/kobject.c:761 vhci_release+0x7b/0xc0 drivers/bluetooth/hci_vhci.c:346 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x11d/0x1d0 kernel/workqueue.c:1559 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Second to last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1491 [inline] __run_timers+0x550/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 The buggy address belongs to the object at ffff888025388000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 96 bytes inside of 8192-byte region [ffff888025388000, ffff88802538a000) The buggy address belongs to the page: page:ffffea000094e200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25388 head:ffffea000094e200 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888016842280 raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000 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 4194, ts 60343510490, free_ts 60095147787 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] hci_alloc_dev_priv+0x23/0x1d20 net/bluetooth/hci_core.c:3775 hci_alloc_dev include/net/bluetooth/hci_core.h:1242 [inline] __vhci_create_device drivers/bluetooth/hci_vhci.c:102 [inline] vhci_create_device+0x122/0x5c0 drivers/bluetooth/hci_vhci.c:153 vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline] vhci_write+0x391/0x450 drivers/bluetooth/hci_vhci.c:290 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 put_page include/linux/mm.h:1258 [inline] __skb_frag_unref include/linux/skbuff.h:3254 [inline] skb_release_data+0x3fa/0x850 net/core/skbuff.c:672 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x4c/0x60 net/core/skbuff.c:756 sk_eat_skb include/net/sock.h:2778 [inline] tcp_recvmsg_locked+0x14d5/0x2760 net/ipv4/tcp.c:2517 tcp_recvmsg+0x350/0x710 net/ipv4/tcp.c:2563 inet_recvmsg+0x136/0x1e0 net/ipv4/af_inet.c:868 sock_recvmsg_nosec net/socket.c:966 [inline] sock_recvmsg net/socket.c:984 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:1057 call_read_iter include/linux/fs.h:2166 [inline] new_sync_read fs/read_write.c:404 [inline] vfs_read+0x725/0xcf0 fs/read_write.c:485 ksys_read+0x14d/0x250 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Memory state around the buggy address: ffff888025387f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025387f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888025388000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888025388080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888025388100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================