================================================================== 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+0xe87/0x1060 kernel/locking/mutex.c:760 Read of size 8 at addr ffff888054d58b20 by task kworker/2:4/7271 CPU: 2 UID: 0 PID: 7271 Comm: kworker/2:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 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+0xe87/0x1060 kernel/locking/mutex.c:760 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 13333: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6886 l2cap_conn_add include/net/bluetooth/hci_core.h:1672 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7077 l2cap_sock_connect+0x3ba/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x107/0x180 net/socket.c:3659 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x821/0xaa0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x423/0x670 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file+0x141/0x1a0 net/socket.c:2089 __sys_connect+0x13b/0x160 net/socket.c:2108 __do_sys_connect net/socket.c:2114 [inline] __se_sys_connect net/socket.c:2111 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2111 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 13760: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4894 l2cap_conn_free net/bluetooth/l2cap_core.c:1811 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1823 [inline] l2cap_conn_del+0x59c/0x730 net/bluetooth/l2cap_core.c:1803 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7325 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7318 hci_disconn_cfm include/net/bluetooth/hci_core.h:2118 [inline] hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2599 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5301 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:501 hci_unregister_dev+0x227/0x640 net/bluetooth/hci_core.c:2715 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x7a/0x100 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+0x419/0x4e0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888054d58800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff888054d58800, ffff888054d58c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54d58 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b042dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b042dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001535601 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 5947, tgid 5947 (syz-executor), ts 55332180689, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4382 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:950 qdisc_create_dflt+0x94/0x490 net/sched/sch_generic.c:1012 attach_one_default_qdisc net/sched/sch_generic.c:1178 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2660 [inline] attach_default_qdiscs net/sched/sch_generic.c:1196 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1255 __dev_open+0x432/0x7c0 net/core/dev.c:1691 __dev_change_flags+0x55d/0x720 net/core/dev.c:9549 netif_change_flags+0x8d/0x160 net/core/dev.c:9612 do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3143 rtnl_changelink net/core/rtnetlink.c:3761 [inline] __rtnl_newlink net/core/rtnetlink.c:3920 [inline] rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4057 page_owner free stack trace missing Memory state around the buggy address: ffff888054d58a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054d58a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888054d58b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054d58b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054d58c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================