BUG: soft lockup in sys_recvmsg (3)

Status: premoderation: reported on 2026/10/10 00:25
Reported-by: syzbot+ef305766b4e4f4dba2e3@syzkaller.appspotmail.com
First crash: 5h03m, last: 5h03m
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in sys_recvmsg 1 10 840d 927d 0/2 auto-obsoleted due to no activity on 2024/09/19 17:52
android-5-10 BUG: soft lockup in sys_recvmsg (2) 1 syz, C error 2 355d 535d 0/2 auto-obsoleted due to no activity on 2026/01/28 03:20
android-5-10 BUG: soft lockup in sys_recvmsg 1 4 824d 903d 0/2 auto-obsoleted due to no activity on 2024/10/05 13:04
linux-5.15 INFO: rcu detected stall in sys_recvmsg 1 7 45d 425d 0/3 upstream: reported on 2025/08/10 06:16
linux-6.1 INFO: rcu detected stall in sys_recvmsg 1 1 449d 449d 0/3 auto-obsoleted due to no activity on 2025/10/25 13:40
linux-6.1 INFO: rcu detected stall in sys_recvmsg (2) 1 1 102d 102d 0/3 auto-obsoleted due to no activity on 2026/10/08 01:20
linux-6.6 INFO: rcu detected stall in sys_recvmsg 1 2 408d 408d 0/2 auto-obsoleted due to no activity on 2025/12/05 18:53
linux-6.6 INFO: rcu detected stall in sys_recvmsg (2) 1 1 5d20h 5d20h 0/2 upstream: reported on 2026/10/04 09:06

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.4.13909:23705]
Modules linked in:
CPU: 0 PID: 23705 Comm: syz.4.13909 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:356 [inline]
RIP: 0010:__rcu_read_lock+0x1b/0x50 kernel/rcu/tree_plugin.h:376
Code: c5 fb ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 48 89 e5 53 65 48 8b 1d e3 d0 af 7e 48 81 c3 08 04 00 00 48 89 d8 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 05 ff 03 5b 5d
RSP: 0018:ffffc900010fe328 EFLAGS: 00000a02
RAX: 1ffff1102272a301 RBX: ffff888113951808 RCX: ffff888113951400
RDX: 0000000000000000 RSI: 000000007c85a2af RDI: ffff8881284f6040
RBP: ffffc900010fe330 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200021fc78 R12: dffffc0000000000
R13: ffff88813f00c501 R14: 0000000000000022 R15: 000000007c85a2af
FS:  00007f54f59d36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54f59d2ff8 CR3: 00000001350a6000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000200000000900 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 rcu_read_lock include/linux/rcupdate.h:716 [inline]
 net_generic include/net/netns/generic.h:44 [inline]
 tipc_sk_lookup+0xa1/0x600 net/tipc/socket.c:2999
 tipc_sk_rcv+0x350/0x1df0 net/tipc/socket.c:2494
 tipc_node_xmit+0x36c/0xd80 net/tipc/node.c:1679
 tipc_node_xmit_skb net/tipc/node.c:1744 [inline]
 tipc_node_distr_xmit+0x277/0x390 net/tipc/node.c:1759
 tipc_sk_rcv+0x1913/0x1df0 net/tipc/socket.c:2503
 tipc_node_xmit+0x36c/0xd80 net/tipc/node.c:1679
 tipc_sk_push_backlog+0x4d3/0x7b0 net/tipc/socket.c:1307
 tipc_sk_conn_proto_rcv net/tipc/socket.c:1362 [inline]
 tipc_sk_proto_rcv+0xa32/0x1b60 net/tipc/socket.c:2160
 tipc_sk_filter_rcv+0x30bc/0x3860 net/tipc/socket.c:2356
 tipc_sk_enqueue net/tipc/socket.c:2448 [inline]
 tipc_sk_rcv+0x745/0x1df0 net/tipc/socket.c:2499
 tipc_node_xmit+0x36c/0xd80 net/tipc/node.c:1679
 tipc_node_xmit_skb net/tipc/node.c:1744 [inline]
 tipc_node_distr_xmit+0x277/0x390 net/tipc/node.c:1759
 tipc_sk_backlog_rcv+0x174/0x220 net/tipc/socket.c:2416
 sk_backlog_rcv include/net/sock.h:1071 [inline]
 __release_sock+0x146/0x360 net/core/sock.c:2588
 release_sock+0x60/0x1b0 net/core/sock.c:3141
 tipc_wait_for_rcvmsg+0x2d7/0x5e0 net/tipc/socket.c:1853
 tipc_recvstream+0x1f4/0xe70 net/tipc/socket.c:2044
 ____sys_recvmsg+0x2ca/0x5b0 net/socket.c:-1
 ___sys_recvmsg+0x213/0x5c0 net/socket.c:2638
 __sys_recvmsg net/socket.c:2668 [inline]
 __do_sys_recvmsg net/socket.c:2678 [inline]
 __se_sys_recvmsg net/socket.c:2675 [inline]
 __x64_sys_recvmsg+0x1fe/0x2d0 net/socket.c:2675
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f54f6fbc1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f54f59d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f54f7244180 RCX: 00007f54f6fbc1d9
RDX: 0000000000000100 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f54f7053888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54f7244218 R14: 00007f54f7244180 R15: 00007ffee1e7a718
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 23703 Comm: syz.4.13909 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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+0xce/0x130 arch/x86/kernel/kvm.c:926
Code: 38 f0 75 26 41 f7 c4 00 02 00 00 75 0f 0f 1f 44 00 00 0f 00 2d c3 1c b8 03 f4 eb 0e 0f 1f 44 00 00 0f 00 2d b4 1c b8 03 fb f4 <4c> 89 64 24 18 ff 74 24 18 9d 48 c7 44 24 20 0e 36 e0 45 4b c7 04
RSP: 0018:ffffc900010876e0 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff88813f00c588 RCX: ffffffff814bec24
RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffff88813f00c588
RBP: ffffc90001087790 R08: ffff88813f00c588 R09: 1ffff11027e018b1
R10: dffffc0000000000 R11: ffffed1027e018b2 R12: 0000000000000246
R13: 61299361e3f1ebd8 R14: dffffc0000000000 R15: 1ffff92000210ee0
FS:  00007f54f5a156c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54f59f3ff8 CR3: 00000001350a6000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x72d/0xb80 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock include/linux/spinlock.h:184 [inline]
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0xe4/0xf0 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:360 [inline]
 lock_sock_nested+0x90/0x2a0 net/core/sock.c:3124
 lock_sock include/net/sock.h:1697 [inline]
 tipc_sendstream+0x47/0x70 net/tipc/socket.c:1544
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2377
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2431
 __sys_sendmsg net/socket.c:2460 [inline]
 __do_sys_sendmsg net/socket.c:2469 [inline]
 __se_sys_sendmsg net/socket.c:2467 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2467
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f54f6fbc1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f54f5a15028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f54f7243fa0 RCX: 00007f54f6fbc1d9
RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000004
RBP: 00007f54f7053888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54f7244038 R14: 00007f54f7243fa0 R15: 00007ffee1e7a718

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/10 00:25 android13-5.10-lts b677692288f7 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10-perf BUG: soft lockup in sys_recvmsg
* Struck through repros no longer work on HEAD.