BUG: soft lockup in sys_sendto

Status: auto-obsoleted due to no activity on 2023/11/14 13:19
Reported-by: syzbot+2c20f59c7922d0656b29@syzkaller.appspotmail.com
First crash: 1123d, last: 1087d
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in sys_sendto 1 1 779d 779d 0/2 auto-obsoleted due to no activity on 2024/09/16 21:53
linux-5.15 INFO: rcu detected stall in sys_sendto (2) origin:lts-only 1 syz done 2 522d 614d 0/3 upstream: reported syz repro on 2024/12/01 03:42
linux-6.1 INFO: rcu detected stall in sys_sendto (2) origin:upstream 1 syz error 3 15d 237d 0/3 upstream: reported syz repro on 2025/12/12 19:08
upstream INFO: rcu detected stall in sys_sendto (6) net 1 1 987d 987d 0/29 closed as invalid on 2024/02/01 10:31
linux-6.1 INFO: rcu detected stall in sys_sendto origin:upstream 1 syz, C error 1 700d 923d 0/3 auto-obsoleted due to no activity on 2025/10/30 02:21
linux-5.15 INFO: rcu detected stall in sys_sendto 1 1 723d 723d 0/3 auto-obsoleted due to no activity on 2024/11/22 09:09
upstream INFO: rcu detected stall in sys_sendto (7) prio:low wireless mm 1 syz, C error error 402 8d08h 807d 0/29 upstream: reported C repro on 2024/05/21 18:44
upstream INFO: rcu detected stall in sys_sendto (5) perf 1 7 1649d 1770d 0/29 closed as invalid on 2022/02/08 10:00
linux-6.6 INFO: rcu detected stall in sys_sendto origin:lts-only 1 syz, C error 8 11d 346d 0/2 upstream: reported C repro on 2025/08/26 10:53

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz-executor.5:18415]
Modules linked in:
CPU: 0 PID: 18415 Comm: syz-executor.5 Tainted: G        W         5.10.187-syzkaller-00057-g8a427269c016 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline]
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline]
RIP: 0010:kvm_wait+0xfc/0x150 arch/x86/kernel/kvm.c:926
Code: 38 f0 75 26 41 f7 c7 00 02 00 00 75 0f 0f 1f 44 00 00 0f 00 2d e5 46 d5 03 f4 eb 0e 0f 1f 44 00 00 0f 00 2d d6 46 d5 03 fb f4 <4c> 89 7c 24 18 ff 74 24 18 9d 48 c7 44 24 20 0e 36 e0 45 49 c7 04
RSP: 0018:ffffc90005816fc0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff92000b02dfc RCX: 1ffffffff0cd8ddf
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffc90005817000
RBP: ffffc90005817070 R08: dffffc0000000000 R09: ffffed103ee0ae4b
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f7057254 R14: 0000000000000001 R15: 0000000000000246
FS:  00007fb3181136c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001a40 CR3: 0000000112b1c000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
 pv_wait_node kernel/locking/qspinlock_paravirt.h:325 [inline]
 __pv_queued_spin_lock_slowpath+0x407/0xc70 kernel/locking/qspinlock.c:473
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:183 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x139/0x1b0 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:354 [inline]
 __dev_xmit_skb net/core/dev.c:3808 [inline]
 __dev_queue_xmit+0xbc0/0x28e0 net/core/dev.c:4147
 dev_queue_xmit+0x17/0x20 net/core/dev.c:4215
 neigh_resolve_output+0x6b8/0x760 net/core/neighbour.c:1498
 neigh_output include/net/neighbour.h:517 [inline]
 ip_finish_output2+0xb7a/0xfc0 net/ipv4/ip_output.c:237
 __ip_finish_output+0x409/0x740
 ip_finish_output+0x34/0x1e0 net/ipv4/ip_output.c:325
 NF_HOOK_COND include/linux/netfilter.h:288 [inline]
 ip_mc_output+0x3d3/0xa30 net/ipv4/ip_output.c:424
 dst_output include/net/dst.h:437 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0xb0/0x140 net/ipv4/ip_output.c:1590
 udp_send_skb+0x9ae/0x12e0 net/ipv4/udp.c:955
 udp_sendmsg+0x1ce6/0x2a80 net/ipv4/udp.c:1242
 inet_sendmsg+0xa1/0xc0 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x545/0x700 net/socket.c:1987
 __do_sys_sendto net/socket.c:1999 [inline]
 __se_sys_sendto net/socket.c:1995 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:1995
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7fb319390ae9
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:00007fb3181130c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fb3194aff80 RCX: 00007fb319390ae9
RDX: 0000000000000000 RSI: 0000000020001940 RDI: 0000000000000003
RBP: 00007fb3193dc47a R08: 0000000020001a40 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fb3194aff80 R15: 00007fffb3dde4e8
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 18403 Comm: syz-executor.0 Tainted: G        W         5.10.187-syzkaller-00057-g8a427269c016 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x5a1/0xc70 kernel/locking/qspinlock.c:508
Code: 85 ba 01 00 00 c6 03 00 48 8b 44 24 28 42 0f b6 04 30 84 c0 0f 85 bf 01 00 00 48 8b 04 24 c6 00 01 bb 00 80 ff ff eb 06 f3 90 <ff> c3 74 50 43 0f b6 44 35 00 84 c0 75 32 41 80 3c 24 00 75 e9 4c
RSP: 0018:ffffc9000591ebc0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 00000000ffffe868 RCX: ffffffff8150a984
RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffc9000591eb40
RBP: ffffc9000591ecb0 R08: dffffc0000000000 R09: fffffbfff0d9e02e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff86cf016c
R13: 1ffffffff0d9e02d R14: dffffc0000000000 R15: ffff88823ff52180
FS:  00007fc488c386c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f48d52d8ff8 CR3: 000000011424d000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:183 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x139/0x1b0 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 get_dist_table+0x207/0x2e0 net/sched/sch_netem.c:798
 netem_change+0x9d7/0x1fb0 net/sched/sch_netem.c:995
 netem_init+0x5b/0xb0 net/sched/sch_netem.c:1075
 qdisc_create+0x879/0x12d0 net/sched/sch_api.c:1264
 tc_modify_qdisc+0x8a4/0x13f0
 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5571
 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2496
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5589
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1915
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2357
 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2411
 __sys_sendmsg net/socket.c:2440 [inline]
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x1b1/0x280 net/socket.c:2447
 __x64_sys_sendmsg+0x7b/0x90 net/socket.c:2447
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7fc489ed6ae9
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:00007fc488c380c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc489ff6050 RCX: 00007fc489ed6ae9
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000003
RBP: 00007fc489f2247a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fc489ff6050 R15: 00007ffd9ecd20c8

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/16 13:10 android13-5.10-lts 8a427269c016 39990d51 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 BUG: soft lockup in sys_sendto
2023/07/10 17:08 android13-5.10-lts 59b65efafe20 d47e94ee .config console log report info ci2-android-5-10 BUG: soft lockup in sys_sendto
* Struck through repros no longer work on HEAD.