[v5.15] possible deadlock in j1939_sk_errqueue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 09996673e313 Linux 5.15.123
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13a74d06a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=b234d12d7c90a2e8
dashboard link: https://syzkaller.appspot.com/bug?extid=9b2484e79a5f43b4851c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10335af9a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11f300e5a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/20ccf0af5ae0/disk-09996673.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3f784a67f3fb/vmlinux-09996673.xz
kernel image: https://storage.googleapis.com/syzbot-assets/27ac27fd1514/Image-09996673.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9b2484...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.15.123-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor208/5052 is trying to acquire lock:
ffff0000ce3410d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000ce3410d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081

but task is already holding lock:
ffff0000ce341088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff0000ce341088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
ffff0000ce341088 (&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:5462 [inline]
__netif_receive_skb+0x18c/0x400 net/core/dev.c:5576
process_backlog+0x3ec/0x7e0 net/core/dev.c:6453
__napi_poll+0xb4/0x624 net/core/dev.c:7012
napi_poll net/core/dev.c:7079 [inline]
net_rx_action+0x500/0xc10 net/core/dev.c:7166
__do_softirq+0x344/0xe20 kernel/softirq.c:558
run_ksoftirqd+0x68/0x258 kernel/softirq.c:920
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:8863
do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2727
__rtnl_newlink net/core/rtnetlink.c:3407 [inline]
rtnl_newlink+0x1238/0x1ab8 net/core/rtnetlink.c:3522
rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5599
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5617
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:724 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2412
___sys_sendmsg+0x214/0x294 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg net/socket.c:2502 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2502
__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:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
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:3787 [inline]
__lock_acquire+0x32cc/0x7620 kernel/locking/lockdep.c:5011
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622
__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:8863
do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2727
__rtnl_newlink net/core/rtnetlink.c:3407 [inline]
rtnl_newlink+0x1238/0x1ab8 net/core/rtnetlink.c:3522
rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5599
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5617
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:724 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2412
___sys_sendmsg+0x214/0x294 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg net/socket.c:2502 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2502
__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:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
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-executor208/5052:
#0: ffff8000169e7128 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff8000169e7128 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5596
#1: ffff0000ce341088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
#1: ffff0000ce341088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
#1: ffff0000ce341088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_cancel_active_session+0x54/0x414 net/can/j1939/transport.c:2183

stack backtrace:
CPU: 0 PID: 5052 Comm: syz-executor208 Not tainted 5.15.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
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:3787 [inline]
__lock_acquire+0x32cc/0x7620 kernel/locking/lockdep.c:5011
lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5622
__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:8863
do_setlink+0xaa4/0x3164 net/core/rtnetlink.c:2727
__rtnl_newlink net/core/rtnetlink.c:3407 [inline]
rtnl_newlink+0x1238/0x1ab8 net/core/rtnetlink.c:3522
rtnetlink_rcv_msg+0xa74/0xdac net/core/rtnetlink.c:5599
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5617
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:724 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2412
___sys_sendmsg+0x214/0x294 net/socket.c:2466
__sys_sendmsg net/socket.c:2495 [inline]
__do_sys_sendmsg net/socket.c:2504 [inline]
__se_sys_sendmsg net/socket.c:2502 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2502
__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:596
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584


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