Hello, syzbot found the following issue on: HEAD commit: ae230642190a Merge branch 'af_unix-followup-fixes-for-so_p.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=1771bf67280000 kernel config: https://syzkaller.appspot.com/x/.config?x=c9bf1936936ca698 dashboard link: https://syzkaller.appspot.com/bug?extid=1591462f226d9cbf0564 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8c060db03f09/disk-ae230642.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1b9b937ece91/vmlinux-ae230642.xz kernel image: https://storage.googleapis.com/syzbot-assets/0c7eb1c82bf0/bzImage-ae230642.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+1591462f226d9cbf0564@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.4.0-rc7-syzkaller-01948-gae230642190a #0 Not tainted ------------------------------------------------------ syz-executor.2/11224 is trying to acquire lock: ffff88803bee50d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff88803bee50d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081 but task is already holding lock: ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x41/0x360 net/can/j1939/transport.c:2183 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&priv->active_session_list_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1564 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x2bf/0x4d0 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline] j1939_xtp_rx_abort_one+0x3c0/0x5b0 net/can/j1939/transport.c:1351 j1939_xtp_rx_abort net/can/j1939/transport.c:1362 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2111 [inline] j1939_tp_recv+0xd98/0xf50 net/can/j1939/transport.c:2144 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa80 net/can/j1939/main.c:38 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606 can_receive+0x31d/0x5c0 net/can/af_can.c:663 can_rcv+0x1e1/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5452 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5566 process_backlog+0x101/0x670 net/core/dev.c:5894 __napi_poll+0xb7/0x6f0 net/core/dev.c:6460 napi_poll net/core/dev.c:6527 [inline] net_rx_action+0x8a9/0xcb0 net/core/dev.c:6660 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:939 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:931 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #1 (&jsk->sk_session_queue_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0x7f/0x160 net/can/j1939/socket.c:1280 j1939_netdev_notify+0x19f/0x1d0 net/can/j1939/main.c:381 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline] call_netdevice_notifiers net/core/dev.c:2014 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867 __rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 ____sys_sendmsg+0x733/0x920 net/socket.c:2493 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2547 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2576 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&priv->j1939_socks_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3113 [inline] check_prevs_add kernel/locking/lockdep.c:3232 [inline] validate_chain kernel/locking/lockdep.c:3847 [inline] __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088 lock_acquire kernel/locking/lockdep.c:5705 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081 j1939_session_destroy+0x26c/0x4e0 net/can/j1939/transport.c:271 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put net/can/j1939/transport.c:299 [inline] j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline] j1939_session_deactivate_locked+0x293/0x340 net/can/j1939/transport.c:1074 j1939_cancel_active_session+0x183/0x360 net/can/j1939/transport.c:2194 j1939_netdev_notify+0x197/0x1d0 net/can/j1939/main.c:380 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline] call_netdevice_notifiers net/core/dev.c:2014 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867 __rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 ____sys_sendmsg+0x733/0x920 net/socket.c:2493 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2547 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2576 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &priv->j1939_socks_lock --> &jsk->sk_session_queue_lock --> &priv->active_session_list_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&priv->active_session_list_lock); lock(&jsk->sk_session_queue_lock); lock(&priv->active_session_list_lock); lock(&priv->j1939_socks_lock); *** DEADLOCK *** 2 locks held by syz-executor.2/11224: #0: ffffffff8e1194a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8e1194a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e8/0xd50 net/core/rtnetlink.c:6421 #1: ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] #1: ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] #1: ffff88803bee5088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x41/0x360 net/can/j1939/transport.c:2183 stack backtrace: CPU: 1 PID: 11224 Comm: syz-executor.2 Not tainted 6.4.0-rc7-syzkaller-01948-gae230642190a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2188 check_prev_add kernel/locking/lockdep.c:3113 [inline] check_prevs_add kernel/locking/lockdep.c:3232 [inline] validate_chain kernel/locking/lockdep.c:3847 [inline] __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088 lock_acquire kernel/locking/lockdep.c:5705 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081 j1939_session_destroy+0x26c/0x4e0 net/can/j1939/transport.c:271 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put net/can/j1939/transport.c:299 [inline] j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline] j1939_session_deactivate_locked+0x293/0x340 net/can/j1939/transport.c:1074 j1939_cancel_active_session+0x183/0x360 net/can/j1939/transport.c:2194 j1939_netdev_notify+0x197/0x1d0 net/can/j1939/main.c:380 notifier_call_chain+0xb6/0x3c0 kernel/notifier.c:93 call_netdevice_notifiers_info+0xb9/0x130 net/core/dev.c:1962 call_netdevice_notifiers_extack net/core/dev.c:2000 [inline] call_netdevice_notifiers net/core/dev.c:2014 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x19e2/0x3ae0 net/core/rtnetlink.c:2867 __rtnl_newlink+0xd85/0x1860 net/core/rtnetlink.c:3655 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3702 rtnetlink_rcv_msg+0x43d/0xd50 net/core/rtnetlink.c:6424 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2549 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 ____sys_sendmsg+0x733/0x920 net/socket.c:2493 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2547 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2576 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fdb2bc8c389 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdb2cab9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdb2bdabf80 RCX: 00007fdb2bc8c389 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000006 RBP: 00007fdb2bcd7493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd70d89bbf R14: 00007fdb2cab9300 R15: 0000000000022000 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
