================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x2cb4/0x3ff0 kernel/locking/lockdep.c:3295 Read of size 8 at addr ffff8880b44d84e0 by task kworker/1:0/19 CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 __lock_acquire+0x2cb4/0x3ff0 kernel/locking/lockdep.c:3295 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] lock_sock_nested+0x3b/0x110 net/core/sock.c:2884 l2cap_sock_teardown_cb+0xa0/0x6d0 net/bluetooth/l2cap_sock.c:1348 l2cap_chan_del+0xbc/0xa50 net/bluetooth/l2cap_core.c:603 l2cap_chan_close+0x1b5/0x950 net/bluetooth/l2cap_core.c:761 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:430 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Allocated by task 8097: __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0xae/0x560 net/core/skbuff.c:205 alloc_skb_fclone include/linux/skbuff.h:1037 [inline] sk_stream_alloc_skb+0xba/0x850 net/ipv4/tcp.c:884 tcp_sendmsg_locked+0xc0b/0x2f60 net/ipv4/tcp.c:1312 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1462 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 sock_write_iter+0x287/0x3c0 net/socket.c:966 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8097: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 skb_free_head net/core/skbuff.c:563 [inline] skb_release_data+0x6de/0x920 net/core/skbuff.c:583 skb_release_all net/core/skbuff.c:640 [inline] __kfree_skb net/core/skbuff.c:654 [inline] consume_skb+0x113/0x3d0 net/core/skbuff.c:714 __dev_kfree_skb_any+0x9c/0xc0 net/core/dev.c:2796 dev_consume_skb_any include/linux/netdevice.h:3567 [inline] napi_consume_skb+0x45d/0x5e0 net/core/skbuff.c:778 free_old_xmit_skbs+0xea/0x270 drivers/net/virtio_net.c:1395 start_xmit+0x156/0x17a0 drivers/net/virtio_net.c:1611 __netdev_start_xmit include/linux/netdevice.h:4349 [inline] netdev_start_xmit include/linux/netdevice.h:4363 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 sch_direct_xmit+0x2d6/0xf70 net/sched/sch_generic.c:332 qdisc_restart net/sched/sch_generic.c:395 [inline] __qdisc_run+0x4d0/0x1640 net/sched/sch_generic.c:403 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:3451 [inline] __dev_queue_xmit+0x2102/0x2e00 net/core/dev.c:3807 neigh_hh_output include/net/neighbour.h:491 [inline] neigh_output include/net/neighbour.h:499 [inline] ip_finish_output2+0xb6d/0x15a0 net/ipv4/ip_output.c:230 ip_finish_output+0xae9/0x10b0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_output+0x203/0x5f0 net/ipv4/ip_output.c:406 dst_output include/net/dst.h:455 [inline] ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x91e/0x1c10 net/ipv4/ip_output.c:507 __tcp_transmit_skb+0x1b9c/0x3400 net/ipv4/tcp_output.c:1148 tcp_transmit_skb net/ipv4/tcp_output.c:1164 [inline] tcp_write_xmit+0x989/0x5100 net/ipv4/tcp_output.c:2391 __tcp_push_pending_frames+0xae/0x310 net/ipv4/tcp_output.c:2572 tcp_push+0x4b7/0x6b0 net/ipv4/tcp.c:745 tcp_sendmsg_locked+0x26b3/0x2f60 net/ipv4/tcp.c:1432 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1462 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 sock_write_iter+0x287/0x3c0 net/socket.c:966 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880b44d8440 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff8880b44d8440, ffff8880b44d8c40) The buggy address belongs to the page: page:ffffea0002d13600 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0xffff8880b44d9540 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002451308 ffffea0002ae5d88 ffff88813bff0c40 raw: ffff8880b44d9540 ffff8880b44d8440 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880b44d8380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880b44d8400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8880b44d8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880b44d8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880b44d8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================