================================================================== 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:681 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:747 Read of size 8 at addr ffff888056315b20 by task kworker/0:1/10 CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.16.0-rc5-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:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] __mutex_lock_common kernel/locking/mutex.c:681 [inline] __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:747 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 8721: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 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:6870 l2cap_conn_add include/net/bluetooth/hci_core.h:1638 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7061 l2cap_sock_connect+0x3b7/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x104/0x180 net/socket.c:3608 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:2038 __sys_connect+0x13b/0x160 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6780: 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:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 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:7309 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7302 hci_disconn_cfm include/net/bluetooth/hci_core.h:2071 [inline] hci_conn_hash_flush+0x10b/0x260 net/bluetooth/hci_conn.c:2560 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5294 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:501 hci_unregister_dev+0x227/0x640 net/bluetooth/hci_core.c:2717 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x14d/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86c/0x2bd0 kernel/exit.c:964 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888056315800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff888056315800, ffff888056315c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x56310 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 ffff88801b842dc0 ffffea0000994e00 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842dc0 ffffea0000994e00 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000158c401 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 5955, tgid 5955 (syz-executor), ts 53637903852, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_noprof+0x2ed/0x500 mm/slub.c:4334 kmalloc_node_noprof include/linux/slab.h:932 [inline] qdisc_alloc+0xbb/0xc50 net/sched/sch_generic.c:948 qdisc_create_dflt+0x94/0x490 net/sched/sch_generic.c:1010 attach_one_default_qdisc net/sched/sch_generic.c:1176 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2655 [inline] attach_default_qdiscs net/sched/sch_generic.c:1194 [inline] dev_activate+0x63f/0x12d0 net/sched/sch_generic.c:1253 __dev_open+0x43a/0x7d0 net/core/dev.c:1692 __dev_change_flags+0x55d/0x720 net/core/dev.c:9458 netif_change_flags+0x8d/0x160 net/core/dev.c:9521 do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3141 rtnl_changelink net/core/rtnetlink.c:3759 [inline] __rtnl_newlink net/core/rtnetlink.c:3918 [inline] rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4055 page_owner free stack trace missing Memory state around the buggy address: ffff888056315a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056315a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888056315b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888056315b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056315c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================