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: [email protected]
======================================================
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>
---
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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:
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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
syzbot has found a reproducer for the following issue on:
HEAD commit: e40939bbfc68 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=17ce67d8a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c84f463eb74eab24
dashboard link: https://syzkaller.appspot.com/bug?extid=1591462f226d9cbf0564
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1580fc5ca80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178f78d4a80000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/257596b75aaf/disk-e40939bb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9c75b8d61081/vmlinux-e40939bb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8f0233129f4f/Image-e40939bb.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc7-syzkaller-ge40939bbfc68 #0 Not tainted
------------------------------------------------------
syz-executor375/6045 is trying to acquire lock:
ffff0000d2e690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff0000d2e690d0 (&priv->j1939_socks_lock){+.-.}-{2:2}, at: j1939_sk_errqueue+0x90/0x144 net/can/j1939/socket.c:1081
but task is already holding lock:
ffff0000d2e69088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
ffff0000d2e69088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
ffff0000d2e69088 (&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:126 [inline]
_raw_spin_lock_bh+0x48/0x60 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+0x60/0x378 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+0x5bc/0x930 net/can/j1939/main.c:112
deliver net/can/af_can.c:572 [inline]
can_rcv_filter+0x308/0x714 net/can/af_can.c:606
can_receive+0x338/0x498 net/can/af_can.c:663
can_rcv+0x128/0x23c net/can/af_can.c:687
__netif_receive_skb_one_core net/core/dev.c:5493 [inline]
__netif_receive_skb+0x18c/0x400 net/core/dev.c:5607
process_backlog+0x3c0/0x70c net/core/dev.c:5935
__napi_poll+0xb4/0x648 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x5e4/0xdc4 net/core/dev.c:6698
__do_softirq+0x2d0/0xd54 kernel/softirq.c:571
run_ksoftirqd+0x6c/0x158 kernel/softirq.c:939
smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
kthread+0x288/0x310 kernel/kthread.c:379
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:853
-> #1 (&jsk->sk_session_queue_lock){+.-.}-{2:2}:
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x48/0x60 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:355 [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:381
notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93
raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461
__dev_notify_flags+0x2bc/0x544
dev_change_flags+0xd0/0x15c net/core/dev.c:8645
do_setlink+0xc68/0x35c8 net/core/rtnetlink.c:2867
__rtnl_newlink net/core/rtnetlink.c:3648 [inline]
rtnl_newlink+0x1354/0x1b1c net/core/rtnetlink.c:3695
rtnetlink_rcv_msg+0x744/0xdb8 net/core/rtnetlink.c:6417
netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6435
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x568/0x81c net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x26c/0x33c net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2593
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
-> #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+0x3308/0x7604 kernel/locking/lockdep.c:5088
lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x48/0x60 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:355 [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+0xf0/0x4b4 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:380
notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93
raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461
__dev_notify_flags+0x2bc/0x544
dev_change_flags+0xd0/0x15c net/core/dev.c:8645
do_setlink+0xc68/0x35c8 net/core/rtnetlink.c:2867
__rtnl_newlink net/core/rtnetlink.c:3648 [inline]
rtnl_newlink+0x1354/0x1b1c net/core/rtnetlink.c:3695
rtnetlink_rcv_msg+0x744/0xdb8 net/core/rtnetlink.c:6417
netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6435
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x568/0x81c net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x26c/0x33c net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2593
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
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-executor375/6045:
#0: ffff80009080db68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline]
#0: ffff80009080db68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x700/0xdb8 net/core/rtnetlink.c:6414
#1: ffff0000d2e69088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline]
#1: ffff0000d2e69088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
#1: ffff0000d2e69088 (&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: 6045 Comm: syz-executor375 Not tainted 6.4.0-rc7-syzkaller-ge40939bbfc68 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call trace:
dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
dump_stack+0x1c/0x28 lib/dump_stack.c:113
print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2066
check_noncircular+0x2cc/0x378 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+0x3308/0x7604 kernel/locking/lockdep.c:5088
lock_acquire+0x23c/0x71c kernel/locking/lockdep.c:5705
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x48/0x60 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:355 [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+0xf0/0x4b4 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:380
notifier_call_chain+0x1a4/0x510 kernel/notifier.c:93
raw_notifier_call_chain+0x3c/0x50 kernel/notifier.c:461
__dev_notify_flags+0x2bc/0x544
dev_change_flags+0xd0/0x15c net/core/dev.c:8645
do_setlink+0xc68/0x35c8 net/core/rtnetlink.c:2867
__rtnl_newlink net/core/rtnetlink.c:3648 [inline]
rtnl_newlink+0x1354/0x1b1c net/core/rtnetlink.c:3695
rtnetlink_rcv_msg+0x744/0xdb8 net/core/rtnetlink.c:6417
netlink_rcv_skb+0x214/0x3c4 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6435
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x660/0x8d4 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x568/0x81c net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x26c/0x33c net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__arm64_sys_sendmsg+0x80/0x94 net/socket.c:2593
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x244 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:191
el0_svc+0x4c/0x160 arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
> On Mon, 10 Jul 2023 10:53:57 -0700
>> HEAD commit: e40939bbfc68 Merge branch 'for-next/core' into for-kernelci
>> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178f78d4a80000
>
> Put session without the session list lock held.
>
> #syz test https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git e40939bbfc68
Your commands are accepted, but please keep [email protected] mailing list in CC next time. It serves as a history of what happened with each bug report. Thank you.
>
> --- x/net/can/j1939/transport.c
> +++ y/net/can/j1939/transport.c
> @@ -1083,7 +1083,6 @@ static bool j1939_session_deactivate_loc
>
> list_del_init(&session->active_session_list_entry);
> session->state = J1939_SESSION_DONE;
> - j1939_session_put(session);
> }
>
> return active;
> @@ -1098,6 +1097,9 @@ static bool j1939_session_deactivate(str
> active = j1939_session_deactivate_locked(session);
> j1939_session_list_unlock(priv);
>
> + if (active)
> + j1939_session_put(session);
> +
> return active;
> }
>
> @@ -2178,6 +2180,7 @@ void j1939_simple_recv(struct j1939_priv
> int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
> {
> struct j1939_session *session, *saved;
> + LIST_HEAD(active);
>
> netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
> j1939_session_list_lock(priv);
> @@ -2191,10 +2194,16 @@ int j1939_cancel_active_session(struct j
> j1939_session_put(session);
>
> session->err = ESHUTDOWN;
> - j1939_session_deactivate_locked(session);
> + if (j1939_session_deactivate_locked(session))
> + list_move(&session->active_session_list_entry, &active);
> }
> }
> j1939_session_list_unlock(priv);
> +
> + list_for_each_entry_safe(session, saved, &active, active_session_list_entry) {
> + list_del_init(&session->active_session_list_entry);
> + j1939_session_put(session);
> + }
> return NOTIFY_DONE;
> }
>
> --
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: [email protected]
Tested on:
commit: e40939bb Merge branch 'for-next/core' into for-kernelci
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12a24702a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c84f463eb74eab24
dashboard link: https://syzkaller.appspot.com/bug?extid=1591462f226d9cbf0564
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
patch: https://syzkaller.appspot.com/x/patch.diff?x=1772e474a80000
Note: testing is done by a robot and is best-effort only.
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: [email protected]
Tested on:
commit: 3f01e9fe Merge tag 'linux-watchdog-6.5-rc2' of git://w..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=130a98a2a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4c2acb092ca90577
dashboard link: https://syzkaller.appspot.com/bug?extid=1591462f226d9cbf0564
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch: https://syzkaller.appspot.com/x/patch.diff?x=1380a782a80000
Note: testing is done by a robot and is best-effort only.