[v6.1] possible deadlock in br_multicast_rcv
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syzbot
Jul 25, 2023, 10:43:56 PM7/25/23
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 5302e81aa209 Linux 6.1.41
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12d1466ea80000
kernel config: https://syzkaller.appspot.com/x/.config?x=773f0dbbc4999ad5
dashboard link: https://syzkaller.appspot.com/bug?extid=714180b17aa12e4b2f6d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0d4c5b598789/disk-5302e81a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e6fc722fbbe4/vmlinux-5302e81a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a18ebb82b176/bzImage-5302e81a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+714180...@syzkaller.appspotmail.com
============================================
WARNING: possible recursive locking detected
6.1.41-syzkaller #0 Not tainted
--------------------------------------------
segctord/26746 is trying to acquire lock:
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3345 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3741 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x1072/0x7590 net/bridge/br_multicast.c:3796
but task is already holding lock:
ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1746
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&br->multicast_lock);
lock(&br->multicast_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
6 locks held by segctord/26746:
#0: ffffffff8ce058a0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xb8/0x1f0 kernel/printk/printk.c:2267
#1: ffffc90000007bc0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#1: ffffc90000007bc0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x6b0 kernel/time/timer.c:1464
#2: ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
#2: ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1746
#3: ffffffff8cf29740 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306
#4: ffffffff8cf29740 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306
#5: ffffffff8cf296e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305
stack backtrace:
CPU: 0 PID: 26746 Comm: segctord Not tainted 6.1.41-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2991 [inline]
check_deadlock kernel/locking/lockdep.c:3034 [inline]
validate_chain+0x4726/0x58e0 kernel/locking/lockdep.c:3819
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
br_ip6_multicast_query net/bridge/br_multicast.c:3345 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3741 [inline]
br_multicast_rcv+0x1072/0x7590 net/bridge/br_multicast.c:3796
br_dev_xmit+0xad5/0x1840 net/bridge/br_device.c:89
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
vlan_dev_hard_start_xmit+0x3da/0x6b0 net/8021q/vlan_dev.c:124
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
br_dev_queue_push_xmit+0x6e6/0x8a0 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:302 [inline]
__br_multicast_send_query+0x2e36/0x46a0 net/bridge/br_multicast.c:1650
br_multicast_send_query+0x502/0x6d0 net/bridge/br_multicast.c:1729
br_multicast_port_query_expired+0x2d4/0x3b0 net/bridge/br_multicast.c:1754
call_timer_fn+0x19e/0x6b0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x2e9/0xa4c kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:console_emit_next_record+0xb70/0xda0 kernel/printk/printk.c:2740
Code: 00 48 8b 5c 24 68 44 0f b6 74 24 1f 4d 85 e4 75 07 e8 c4 0b 1c 00 eb 06 e8 bd 0b 1c 00 fb 48 c7 84 24 a0 00 00 00 0e 36 e0 45 <41> c7 44 1d 00 00 00 00 00 49 c7 44 1d 0a 00 00 00 00 49 c7 44 1d
RSP: 0018:ffffc900155ef6c0 EFLAGS: 00000293
RAX: ffffffff816dcf33 RBX: 1ffff92002abdeec RCX: ffff8880752c5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900155ef970 R08: ffffffff816dcf09 R09: fffffbfff2052c45
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000200
R13: dffffc0000000000 R14: 0000000000000001 R15: ffffc900155ef9e0
console_unlock+0x278/0x6e0 kernel/printk/printk.c:2860
vprintk_emit+0xd1/0x1f0 kernel/printk/printk.c:2268
_printk+0xd1/0x111 kernel/printk/printk.c:2289
__nilfs_msg+0x2a9/0x330 fs/nilfs2/super.c:78
nilfs_segctor_thread+0x27a/0x1130 fs/nilfs2/segment.c:2580
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
----------------
Code disassembly (best guess):
0: 00 48 8b add %cl,-0x75(%rax)
3: 5c pop %rsp
4: 24 68 and $0x68,%al
6: 44 0f b6 74 24 1f movzbl 0x1f(%rsp),%r14d
c: 4d 85 e4 test %r12,%r12
f: 75 07 jne 0x18
11: e8 c4 0b 1c 00 call 0x1c0bda
16: eb 06 jmp 0x1e
18: e8 bd 0b 1c 00 call 0x1c0bda
1d: fb sti
1e: 48 c7 84 24 a0 00 00 movq $0x45e0360e,0xa0(%rsp)
25: 00 0e 36 e0 45
* 2a: 41 c7 44 1d 00 00 00 movl $0x0,0x0(%r13,%rbx,1) <-- trapping instruction
31: 00 00
33: 49 c7 44 1d 0a 00 00 movq $0x0,0xa(%r13,%rbx,1)
3a: 00 00
3c: 49 rex.WB
3d: c7 .byte 0xc7
3e: 44 rex.R
3f: 1d .byte 0x1d
---
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 syzk...@googlegroups.com.
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
syzbot found the following issue on:
HEAD commit: 5302e81aa209 Linux 6.1.41
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12d1466ea80000
kernel config: https://syzkaller.appspot.com/x/.config?x=773f0dbbc4999ad5
dashboard link: https://syzkaller.appspot.com/bug?extid=714180b17aa12e4b2f6d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0d4c5b598789/disk-5302e81a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e6fc722fbbe4/vmlinux-5302e81a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a18ebb82b176/bzImage-5302e81a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+714180...@syzkaller.appspotmail.com
============================================
WARNING: possible recursive locking detected
6.1.41-syzkaller #0 Not tainted
--------------------------------------------
segctord/26746 is trying to acquire lock:
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3345 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3741 [inline]
ffff88808c425338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x1072/0x7590 net/bridge/br_multicast.c:3796
but task is already holding lock:
ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1746
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&br->multicast_lock);
lock(&br->multicast_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
6 locks held by segctord/26746:
#0: ffffffff8ce058a0 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0xb8/0x1f0 kernel/printk/printk.c:2267
#1: ffffc90000007bc0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:41 [inline]
#1: ffffc90000007bc0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x6b0 kernel/time/timer.c:1464
#2: ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
#2: ffff888084eb9338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1746
#3: ffffffff8cf29740 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306
#4: ffffffff8cf29740 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:306
#5: ffffffff8cf296e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:305
stack backtrace:
CPU: 0 PID: 26746 Comm: segctord Not tainted 6.1.41-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2991 [inline]
check_deadlock kernel/locking/lockdep.c:3034 [inline]
validate_chain+0x4726/0x58e0 kernel/locking/lockdep.c:3819
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:350 [inline]
br_ip6_multicast_query net/bridge/br_multicast.c:3345 [inline]
br_multicast_ipv6_rcv net/bridge/br_multicast.c:3741 [inline]
br_multicast_rcv+0x1072/0x7590 net/bridge/br_multicast.c:3796
br_dev_xmit+0xad5/0x1840 net/bridge/br_device.c:89
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
vlan_dev_hard_start_xmit+0x3da/0x6b0 net/8021q/vlan_dev.c:124
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3595 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611
__dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
br_dev_queue_push_xmit+0x6e6/0x8a0 net/bridge/br_forward.c:53
NF_HOOK include/linux/netfilter.h:302 [inline]
__br_multicast_send_query+0x2e36/0x46a0 net/bridge/br_multicast.c:1650
br_multicast_send_query+0x502/0x6d0 net/bridge/br_multicast.c:1729
br_multicast_port_query_expired+0x2d4/0x3b0 net/bridge/br_multicast.c:1754
call_timer_fn+0x19e/0x6b0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1790
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1803
__do_softirq+0x2e9/0xa4c kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:console_emit_next_record+0xb70/0xda0 kernel/printk/printk.c:2740
Code: 00 48 8b 5c 24 68 44 0f b6 74 24 1f 4d 85 e4 75 07 e8 c4 0b 1c 00 eb 06 e8 bd 0b 1c 00 fb 48 c7 84 24 a0 00 00 00 0e 36 e0 45 <41> c7 44 1d 00 00 00 00 00 49 c7 44 1d 0a 00 00 00 00 49 c7 44 1d
RSP: 0018:ffffc900155ef6c0 EFLAGS: 00000293
RAX: ffffffff816dcf33 RBX: 1ffff92002abdeec RCX: ffff8880752c5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900155ef970 R08: ffffffff816dcf09 R09: fffffbfff2052c45
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000200
R13: dffffc0000000000 R14: 0000000000000001 R15: ffffc900155ef9e0
console_unlock+0x278/0x6e0 kernel/printk/printk.c:2860
vprintk_emit+0xd1/0x1f0 kernel/printk/printk.c:2268
_printk+0xd1/0x111 kernel/printk/printk.c:2289
__nilfs_msg+0x2a9/0x330 fs/nilfs2/super.c:78
nilfs_segctor_thread+0x27a/0x1130 fs/nilfs2/segment.c:2580
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>
----------------
Code disassembly (best guess):
0: 00 48 8b add %cl,-0x75(%rax)
3: 5c pop %rsp
4: 24 68 and $0x68,%al
6: 44 0f b6 74 24 1f movzbl 0x1f(%rsp),%r14d
c: 4d 85 e4 test %r12,%r12
f: 75 07 jne 0x18
11: e8 c4 0b 1c 00 call 0x1c0bda
16: eb 06 jmp 0x1e
18: e8 bd 0b 1c 00 call 0x1c0bda
1d: fb sti
1e: 48 c7 84 24 a0 00 00 movq $0x45e0360e,0xa0(%rsp)
25: 00 0e 36 e0 45
* 2a: 41 c7 44 1d 00 00 00 movl $0x0,0x0(%r13,%rbx,1) <-- trapping instruction
31: 00 00
33: 49 c7 44 1d 0a 00 00 movq $0x0,0xa(%r13,%rbx,1)
3a: 00 00
3c: 49 rex.WB
3d: c7 .byte 0xc7
3e: 44 rex.R
3f: 1d .byte 0x1d
---
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 syzk...@googlegroups.com.
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
syzbot
Nov 2, 2023, 10:43:17 PM11/2/23
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
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