[v6.1] possible deadlock in sch_direct_xmit (2)

2 views
Skip to first unread message

syzbot

unread,
Jan 9, 2024, 1:28:26 PMJan 9
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: 38fb82ecd144 Linux 6.1.71
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11ab434de80000
kernel config: https://syzkaller.appspot.com/x/.config?x=f8d4b3f2bd71350c
dashboard link: https://syzkaller.appspot.com/bug?extid=834304373a84ac317e98
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/44a009057e6d/disk-38fb82ec.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef84f309ccb4/vmlinux-38fb82ec.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c351b9cee4f7/bzImage-38fb82ec.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+834304...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.1.71-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.4/1243 is trying to acquire lock:
ffff88801f69e458 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff88801f69e458 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
ffff88801f69e458 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

but task is already holding lock:
ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(_xmit_ETHER#2);
lock(_xmit_ETHER#2);

*** DEADLOCK ***

May be due to missing lock nesting notation

12 locks held by syz-executor.4/1243:
#0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
#0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#0: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rawv6_send_hdrinc+0xa8b/0x1850 net/ipv6/raw.c:652
#1: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
#1: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#1: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#2: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#2: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:799 [inline]
#2: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216
#3: ffff888023dec258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline]
#3: ffff888023dec258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline]
#3: ffff888023dec258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline]
#3: ffff888023dec258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259
#4: ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline]
#4: ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
#4: ffff888079e0a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
#5: ffff88814b2f07f0 (k-slock-AF_INET6){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline]
#5: ffff88814b2f07f0 (k-slock-AF_INET6){+.-.}-{2:2}, at: icmpv6_xmit_lock net/ipv6/icmp.c:108 [inline]
#5: ffff88814b2f07f0 (k-slock-AF_INET6){+.-.}-{2:2}, at: icmp6_send+0xc10/0x2160 net/ipv6/icmp.c:543
#6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: icmp6_send+0xb70/0x2160 net/ipv6/icmp.c:535
#7: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
#7: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#7: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#8: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
#8: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#8: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: ip6_nd_hdr net/ipv6/ndisc.c:452 [inline]
#8: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: ndisc_send_skb+0x5a8/0x14e0 net/ipv6/ndisc.c:503
#9: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:306 [inline]
#9: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline]
#9: ffffffff8d12a320 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#10: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:799 [inline]
#10: ffffffff8d12a380 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216
#11: ffff88809be2b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline]
#11: ffff88809be2b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline]
#11: ffff88809be2b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline]
#11: ffff88809be2b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259

stack backtrace:
CPU: 1 PID: 1243 Comm: syz-executor.4 Not tainted 6.1.71-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
<TASK>
__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:2983 [inline]
check_deadlock kernel/locking/lockdep.c:3026 [inline]
validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__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]
__netif_tx_lock include/linux/netdevice.h:4304 [inline]
sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
__dev_xmit_skb net/core/dev.c:3854 [inline]
__dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0xedb/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
dst_output include/net/dst.h:444 [inline]
NF_HOOK include/linux/netfilter.h:302 [inline]
ndisc_send_skb+0xbab/0x14e0 net/ipv6/ndisc.c:509
ndisc_solicit+0x48a/0x690
neigh_probe net/core/neighbour.c:1068 [inline]
__neigh_event_send+0xf30/0x1610 net/core/neighbour.c:1235
neigh_event_send_probe include/net/neighbour.h:468 [inline]
neigh_event_send include/net/neighbour.h:474 [inline]
neigh_resolve_output+0x1b0/0x710 net/core/neighbour.c:1540
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0xedb/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
ip6_send_skb+0x12b/0x240 net/ipv6/ip6_output.c:1995
icmp6_send+0x166f/0x2160 net/ipv6/icmp.c:622
__icmpv6_send include/linux/icmpv6.h:28 [inline]
icmpv6_send include/linux/icmpv6.h:49 [inline]
ip6_link_failure+0x38/0x4e0 net/ipv6/route.c:2789
ip_tunnel_xmit+0x1905/0x2ce0 net/ipv4/ip_tunnel.c:819
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
erspan_xmit+0xaa2/0x1530 net/ipv4/ip_gre.c:718
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3627 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643
sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342
__dev_xmit_skb net/core/dev.c:3854 [inline]
__dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0xedb/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
dst_output include/net/dst.h:444 [inline]
NF_HOOK include/linux/netfilter.h:302 [inline]
rawv6_send_hdrinc+0xd15/0x1850 net/ipv6/raw.c:654
rawv6_sendmsg+0x1648/0x2150 net/ipv6/raw.c:912
sock_sendmsg_nosec net/socket.c:716 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x59e/0x8f0 net/socket.c:2499
___sys_sendmsg net/socket.c:2553 [inline]
__sys_sendmsg+0x2a9/0x390 net/socket.c:2582
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f52c447cd29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f52c519e0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f52c45abf80 RCX: 00007f52c447cd29
RDX: 0000000004000800 RSI: 0000000020001800 RDI: 0000000000000003
RBP: 00007f52c44c947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f52c45abf80 R15: 00007ffca95133e8
</TASK>


---
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 report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

syzbot

unread,
Apr 10, 2024, 8:35:24 PMApr 10
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: bf1e3b1cb1e0 Linux 6.1.85
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16e4135b180000
kernel config: https://syzkaller.appspot.com/x/.config?x=d3e21b90946dbbab
dashboard link: https://syzkaller.appspot.com/bug?extid=834304373a84ac317e98
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134744d5180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a993e3180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/75265c862e54/disk-bf1e3b1c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d22ca40ea90/vmlinux-bf1e3b1c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a5fcb5ebd870/bzImage-bf1e3b1c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+834304...@syzkaller.appspotmail.com

============================================
WARNING: possible recursive locking detected
6.1.85-syzkaller #0 Not tainted
--------------------------------------------
syz-executor871/4118 is trying to acquire lock:
ffff88807a065458 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807a065458 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
ffff88807a065458 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

but task is already holding lock:
ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(_xmit_ETHER#2);
lock(_xmit_ETHER#2);

*** DEADLOCK ***

May be due to missing lock nesting notation

12 locks held by syz-executor871/4118:
#0: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rawv6_send_hdrinc+0xa8b/0x1850 net/ipv6/raw.c:652
#1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#2: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#2: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:843 [inline]
#2: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216
#3: ffff888074787258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
#3: ffff888074787258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline]
#3: ffff888074787258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline]
#3: ffff888074787258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259
#4: ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#4: ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4304 [inline]
#4: ffff888019b6a0d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
#5: ffff8880281780b0 (k-slock-AF_INET6){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
#5: ffff8880281780b0 (k-slock-AF_INET6){+...}-{2:2}, at: icmpv6_xmit_lock net/ipv6/icmp.c:108 [inline]
#5: ffff8880281780b0 (k-slock-AF_INET6){+...}-{2:2}, at: icmp6_send+0xc10/0x2160 net/ipv6/icmp.c:543
#6: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#6: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: icmp6_send+0xb70/0x2160 net/ipv6/icmp.c:535
#7: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#7: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#7: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#8: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#8: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#8: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: ip6_nd_hdr net/ipv6/ndisc.c:452 [inline]
#8: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: ndisc_send_skb+0x5a8/0x14e0 net/ipv6/ndisc.c:503
#9: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#9: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#9: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: ip6_finish_output2+0x698/0x1520 net/ipv6/ip6_output.c:119
#10: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
#10: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:843 [inline]
#10: ffffffff8d12aca0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2d6/0x3cf0 net/core/dev.c:4216
#11: ffff88807a4c5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
#11: ffff88807a4c5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline]
#11: ffff88807a4c5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3841 [inline]
#11: ffff88807a4c5258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x131b/0x3cf0 net/core/dev.c:4259

stack backtrace:
CPU: 0 PID: 4118 Comm: syz-executor871 Not tainted 6.1.85-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__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:2983 [inline]
check_deadlock kernel/locking/lockdep.c:3026 [inline]
validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__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:351 [inline]
__netif_tx_lock include/linux/netdevice.h:4304 [inline]
sch_direct_xmit+0x1c0/0x5e0 net/sched/sch_generic.c:340
__dev_xmit_skb net/core/dev.c:3854 [inline]
__dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
neigh_hh_output include/net/neighbour.h:528 [inline]
neigh_output include/net/neighbour.h:542 [inline]
ip6_finish_output2+0xea3/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
dst_output include/net/dst.h:444 [inline]
NF_HOOK include/linux/netfilter.h:302 [inline]
ndisc_send_skb+0xbab/0x14e0 net/ipv6/ndisc.c:509
ndisc_solicit+0x48a/0x690
neigh_probe net/core/neighbour.c:1075 [inline]
__neigh_event_send+0xf30/0x1610 net/core/neighbour.c:1242
neigh_event_send_probe include/net/neighbour.h:468 [inline]
neigh_event_send include/net/neighbour.h:474 [inline]
neigh_resolve_output+0x1b0/0x710 net/core/neighbour.c:1547
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0xedb/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
ip6_send_skb+0x12b/0x240 net/ipv6/ip6_output.c:1995
icmp6_send+0x166f/0x2160 net/ipv6/icmp.c:622
__icmpv6_send include/linux/icmpv6.h:28 [inline]
icmpv6_send include/linux/icmpv6.h:49 [inline]
ip6_link_failure+0x38/0x4e0 net/ipv6/route.c:2789
ip_tunnel_xmit+0x1905/0x2cc0 net/ipv4/ip_tunnel.c:846
__gre_xmit net/ipv4/ip_gre.c:474 [inline]
erspan_xmit+0xaa2/0x1530 net/ipv4/ip_gre.c:723
__netdev_start_xmit include/linux/netdevice.h:4853 [inline]
netdev_start_xmit include/linux/netdevice.h:4867 [inline]
xmit_one net/core/dev.c:3627 [inline]
dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643
sch_direct_xmit+0x2b2/0x5e0 net/sched/sch_generic.c:342
__dev_xmit_skb net/core/dev.c:3854 [inline]
__dev_queue_xmit+0x1ace/0x3cf0 net/core/dev.c:4259
dev_queue_xmit include/linux/netdevice.h:3021 [inline]
neigh_hh_output include/net/neighbour.h:528 [inline]
neigh_output include/net/neighbour.h:542 [inline]
ip6_finish_output2+0xea3/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:201 [inline]
ip6_finish_output+0x6a0/0xa80 net/ipv6/ip6_output.c:212
dst_output include/net/dst.h:444 [inline]
NF_HOOK include/linux/netfilter.h:302 [inline]
rawv6_send_hdrinc+0xd15/0x1850 net/ipv6/raw.c:654
rawv6_sendmsg+0x1648/0x2150 net/ipv6/raw.c:912
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
___sys_sendmsg net/socket.c:2568 [inline]
__sys_sendmmsg+0x3ab/0x730 net/socket.c:2654
__do_sys_sendmmsg net/socket.c:2683 [inline]
__se_sys_sendmmsg net/socket.c:2680 [inline]
__x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f65d7045369
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 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:00007fffa1747ad8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f65d7045369
RDX: 0000000000000002 RSI: 0000000020001e80 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fffa1747b70
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
syz-executor871 (4118) used greatest stack depth: 17848 bytes left


---
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.
Reply all
Reply to author
Forward
0 new messages