netlink: 'syz-executor.4': attribute type 27 has an invalid length. ====================================================== WARNING: possible circular locking dependency detected 5.15.147-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/10683 is trying to acquire lock: ffff0001032bf5d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff0001032bf5d0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_drop_all+0x4c/0x200 net/can/j1939/socket.c:139 but task is already holding lock: ffff0000ca5cd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff0000ca5cd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x3c/0x144 net/can/j1939/socket.c:1274 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&priv->j1939_socks_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081 __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put+0xf8/0x4f0 net/can/j1939/transport.c:299 j1939_session_deactivate_locked net/can/j1939/transport.c:1086 [inline] j1939_cancel_active_session+0x2ec/0x414 net/can/j1939/transport.c:2194 j1939_netdev_notify+0xe8/0x144 net/can/j1939/main.c:376 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8886 do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2741 rtnl_group_changelink net/core/rtnetlink.c:3270 [inline] __rtnl_newlink net/core/rtnetlink.c:3439 [inline] rtnl_newlink+0xd8c/0x1af4 net/core/rtnetlink.c:3549 rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5630 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5648 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x584/0x870 net/socket.c:2431 ___sys_sendmsg+0x214/0x294 net/socket.c:2485 __sys_sendmsg net/socket.c:2514 [inline] __do_sys_sendmsg net/socket.c:2523 [inline] __se_sys_sendmsg net/socket.c:2521 [inline] __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #1 (&priv->active_session_list_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x60/0x388 net/can/j1939/transport.c:1564 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x230/0x3b4 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next net/can/j1939/transport.c:1108 [inline] j1939_session_completed net/can/j1939/transport.c:1222 [inline] j1939_xtp_rx_eoma_one net/can/j1939/transport.c:1395 [inline] j1939_xtp_rx_eoma+0x2c0/0x4c0 net/can/j1939/transport.c:1410 j1939_tp_cmd_recv net/can/j1939/transport.c:2099 [inline] j1939_tp_recv+0x714/0xe14 net/can/j1939/transport.c:2144 j1939_can_recv+0x568/0x8b4 net/can/j1939/main.c:108 deliver net/can/af_can.c:574 [inline] can_rcv_filter+0x308/0x714 net/can/af_can.c:608 can_receive+0x344/0x4a0 net/can/af_can.c:665 can_rcv+0x118/0x274 net/can/af_can.c:696 __netif_receive_skb_one_core net/core/dev.c:5485 [inline] __netif_receive_skb+0x18c/0x400 net/core/dev.c:5599 process_backlog+0x3ec/0x7e0 net/core/dev.c:6476 __napi_poll+0xb4/0x624 net/core/dev.c:7035 napi_poll net/core/dev.c:7102 [inline] net_rx_action+0x500/0xc10 net/core/dev.c:7189 __do_softirq+0x344/0xdb0 kernel/softirq.c:558 run_ksoftirqd+0x68/0x258 kernel/softirq.c:921 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 -> #0 (&jsk->sk_session_queue_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_sk_queue_drop_all+0x4c/0x200 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0xe0/0x144 net/can/j1939/socket.c:1280 j1939_netdev_notify+0xf0/0x144 net/can/j1939/main.c:377 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8886 do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2741 rtnl_group_changelink net/core/rtnetlink.c:3270 [inline] __rtnl_newlink net/core/rtnetlink.c:3439 [inline] rtnl_newlink+0xd8c/0x1af4 net/core/rtnetlink.c:3549 rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5630 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5648 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x584/0x870 net/socket.c:2431 ___sys_sendmsg+0x214/0x294 net/socket.c:2485 __sys_sendmsg net/socket.c:2514 [inline] __do_sys_sendmsg net/socket.c:2523 [inline] __se_sys_sendmsg net/socket.c:2521 [inline] __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 other info that might help us debug this: Chain exists of: &jsk->sk_session_queue_lock --> &priv->active_session_list_lock --> &priv->j1939_socks_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&priv->j1939_socks_lock); lock(&priv->active_session_list_lock); lock(&priv->j1939_socks_lock); lock(&jsk->sk_session_queue_lock); *** DEADLOCK *** 2 locks held by syz-executor.4/10683: #0: ffff800016a094a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffff800016a094a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5627 #1: ffff0000ca5cd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #1: ffff0000ca5cd0d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_netdev_event_netdown+0x3c/0x144 net/can/j1939/socket.c:1274 stack backtrace: CPU: 1 PID: 10683 Comm: syz-executor.4 Not tainted 5.15.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2011 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x32d4/0x7638 kernel/locking/lockdep.c:5012 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] j1939_sk_queue_drop_all+0x4c/0x200 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0xe0/0x144 net/can/j1939/socket.c:1280 j1939_netdev_notify+0xf0/0x144 net/can/j1939/main.c:377 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 __dev_notify_flags+0x2ac/0x534 dev_change_flags+0xc8/0x154 net/core/dev.c:8886 do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2741 rtnl_group_changelink net/core/rtnetlink.c:3270 [inline] __rtnl_newlink net/core/rtnetlink.c:3439 [inline] rtnl_newlink+0xd8c/0x1af4 net/core/rtnetlink.c:3549 rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5630 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5648 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x584/0x870 net/socket.c:2431 ___sys_sendmsg+0x214/0x294 net/socket.c:2485 __sys_sendmsg net/socket.c:2514 [inline] __do_sys_sendmsg net/socket.c:2523 [inline] __se_sys_sendmsg net/socket.c:2521 [inline] __arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584