syzbot


possible deadlock in j1939_sk_errqueue

Status: upstream: reported C repro on 2023/07/28 13:47
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+9b2484e79a5f43b4851c@syzkaller.appspotmail.com
First crash: 283d, last: 107d
Bug presence (1)
Date Name Commit Repro Result
2024/05/03 upstream (ToT) f03359bca01b C [report] unregister_netdevice: waiting for DEV to become free
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in j1939_sk_errqueue origin:lts-only C inconclusive 6 73d 302d 0/3 upstream: reported C repro on 2023/07/09 02:39
upstream possible deadlock in j1939_sk_errqueue can C unreliable 227 404d 941d 22/26 fixed on 2023/06/08 14:41
upstream possible deadlock in j1939_sk_errqueue (2) can C done 24 81d 307d 26/26 fixed on 2024/03/26 17:39
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/12/17 18:06 1m fix candidate upstream error job log (0)
2023/08/26 22:07 14m fix candidate upstream error job log (0)

Sample crash report:
netlink: 'syz-executor658': attribute type 27 has an invalid length.
======================================================
WARNING: possible circular locking dependency detected
5.15.147-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor658/3986 is trying to acquire lock:
ffff0000caf790d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000caf790d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081

but task is already holding lock:
ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x54/0x414 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: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

-> #1 (&jsk->sk_session_queue_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_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

-> #0 (&priv->j1939_socks_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_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

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-executor658/3986:
 #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: ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
 #1: ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
 #1: ffff0000caf79088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x54/0x414 net/can/j1939/transport.c:2183

stack backtrace:
CPU: 1 PID: 3986 Comm: syz-executor658 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_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

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/20 06:11 linux-5.15.y ddcaf4999061 9bd8dcda .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in j1939_sk_errqueue
2024/01/19 09:27 linux-5.15.y ddcaf4999061 21772ce4 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in j1939_sk_errqueue
2023/07/28 13:47 linux-5.15.y 09996673e313 92476829 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in j1939_sk_errqueue
2023/07/28 14:35 linux-5.15.y 09996673e313 92476829 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in j1939_sk_errqueue
2024/01/01 10:26 linux-5.15.y d93fa2c78854 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in j1939_sk_errqueue
2023/12/31 18:25 linux-5.15.y d93fa2c78854 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in j1939_sk_errqueue
* Struck through repros no longer work on HEAD.