syzbot


INFO: rcu detected stall in sendmsg (5)

Status: upstream: reported syz repro on 2025/06/23 07:43
Reported-by: syzbot+ddb3e33c76ab8ecb85a3@syzkaller.appspotmail.com
First crash: 108d, last: 3d21h
Bug presence (1)
Date Name Commit Repro Result
2025/09/10 upstream (ToT) 9dd1835ecda5 syz Didn't crash
Similar bugs (21)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in sendmsg (3) 1 4 372d 439d 0/3 auto-obsoleted due to no activity on 2025/01/09 18:13
upstream INFO: rcu detected stall in sendmsg net 1 1 1464d 1464d 0/29 auto-closed as invalid on 2022/01/03 17:11
linux-6.6 INFO: rcu detected stall in sendmsg 1 2 47d 69d 0/2 upstream: reported on 2025/07/31 17:16
linux-6.1 INFO: rcu detected stall in sendmsg (4) 1 2 212d 223d 0/3 auto-obsoleted due to no activity on 2025/06/19 03:57
linux-6.1 INFO: rcu detected stall in sendmsg (2) 1 1 562d 562d 0/3 auto-obsoleted due to no activity on 2024/07/04 03:49
upstream INFO: rcu detected stall in sendmsg (2) batman 1 1 1335d 1335d 0/29 auto-closed as invalid on 2022/05/13 12:25
upstream INFO: rcu detected stall in sendmsg (4) mm net 1 C error 59 23d 503d 0/29 upstream: reported C repro on 2024/05/24 06:18
upstream INFO: rcu detected stall in sendmsg (3) net 1 4 611d 695d 0/29 auto-obsoleted due to no activity on 2024/05/05 18:15
linux-5.15 INFO: rcu detected stall in sys_sendmsg origin:upstream 1 C error 15 12d 568d 0/3 upstream: reported C repro on 2024/03/19 21:37
linux-6.1 INFO: rcu detected stall in sendmsg 1 1 796d 796d 0/3 auto-obsoleted due to no activity on 2023/11/12 19:28
upstream BUG: soft lockup in sys_sendmsg (2) net 1 syz 17 15d 126d 0/29 upstream: reported syz repro on 2025/06/05 02:15
upstream INFO: rcu detected stall in sys_sendmsg (2) cgroups mm 1 5 2136d 2137d 0/29 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in sys_sendmsg (3) kernel 1 1 2101d 2101d 0/29 closed as invalid on 2020/01/08 05:33
linux-6.1 INFO: rcu detected stall in sys_sendmsg 1 6 376d 462d 0/3 auto-obsoleted due to no activity on 2025/01/06 11:24
upstream INFO: rcu detected stall in sys_sendmsg net 1 C done 2 2217d 2217d 13/29 fixed on 2019/10/09 10:54
android-6-1 BUG: soft lockup in sys_sendmsg origin:upstream 1 C 3 520d 548d 0/2 upstream: reported C repro on 2024/04/09 06:46
linux-6.1 BUG: soft lockup in sys_sendmsg 1 2 849d 856d 0/3 auto-obsoleted due to no activity on 2023/09/20 17:26
android-5-10 BUG: soft lockup in sys_sendmsg 1 C error 55 10d 566d 0/2 upstream: reported C repro on 2024/03/22 10:41
upstream BUG: soft lockup in sys_sendmsg tipc batman 1 C 3 563d 605d 25/29 fixed on 2024/05/22 23:36
android-5-15 BUG: soft lockup in sys_sendmsg origin:upstream 1 C error 13 392d 566d 0/2 upstream: reported C repro on 2024/03/22 10:44
linux-6.1 BUG: soft lockup in sys_sendmsg (2) origin:upstream 1 C done 1 550d 550d 3/3 fixed on 2024/05/15 09:17

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2645 jiffies s: 87577 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 17687 Comm: syz.7.3328 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:bpf_prog_array_valid include/linux/trace_events.h:444 [inline]
RIP: 0010:perf_trace_preemptirq_template+0x103/0x330 include/trace/events/preemptirq.h:14
Code: d4 49 00 4d 8d a5 80 00 00 00 4c 89 e0 48 c1 e8 03 48 8b 0c 24 49 03 0e 48 89 0c 24 80 3c 18 00 74 08 4c 89 e7 e8 cd d4 49 00 <49> 83 3c 24 00 75 23 4c 8b 34 24 4c 89 f0 48 c1 e8 03 80 3c 18 00
RSP: 0018:ffffc900000078e0 EFLAGS: 00000046
RAX: 1ffffffff196fa4c RBX: dffffc0000000000 RCX: ffffe8ffffc36e30
RDX: 0000000000000000 RSI: ffffffff8adefd00 RDI: ffffffff8adefcc0
RBP: ffffc900000079a8 R08: dffffc0000000000 R09: ffffed10171c6afa
R10: ffffed10171c6afa R11: 1ffff110171c6af9 R12: ffffffff8cb7d260
R13: ffffffff8cb7d1e0 R14: ffffffff8c5e4980 R15: 1ffff92000000f20
FS:  00007f4a1e0b26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffdfa50000 CR3: 0000000033cba000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x84/0x500 kernel/rcu/tree_plugin.h:685
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 2d 97 96 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007aa0 EFLAGS: 00000206
RAX: ee6d40cb09e4bb00 RBX: 1ffff92000000f5c RCX: ee6d40cb09e4bb00
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: ffffffff8adefd20
RBP: ffffc90000007b90 R08: dffffc0000000000 R09: fffffbfff215c44d
R10: fffffbfff215c44d R11: 1ffffffff215c44c R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2147
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_run_softirq+0x183/0x2a0 kernel/time/hrtimer.c:1828
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:___slab_alloc+0x393/0x1230 mm/slub.c:3107
Code: 48 c7 44 24 70 00 00 00 00 9c 8f 44 24 70 f7 44 24 70 00 02 00 00 0f 85 de 02 00 00 f7 c5 00 02 00 00 74 01 fb 49 83 7d 18 00 <0f> 84 6c 05 00 00 48 c7 44 24 70 00 00 00 00 9c 8f 44 24 70 48 8b
RSP: 0018:ffffc90004bff338 EFLAGS: 00000286
RAX: ee6d40cb09e4bb00 RBX: ffff8881401ca000 RCX: ee6d40cb09e4bb00
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: ffffffff8adefd20
RBP: 0000000000000246 R08: dffffc0000000000 R09: fffffbfff215c44d
R10: fffffbfff215c44d R11: 1ffffffff215c44c R12: ffff888063f8d940
R13: ffff8880b8e44400 R14: ffffffff7fff0000 R15: ffff8880b8e44420
 __slab_alloc mm/slub.c:3240 [inline]
 slab_alloc_node mm/slub.c:3325 [inline]
 kmem_cache_alloc_node+0x1e5/0x320 mm/slub.c:3404
 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 nlmsg_new include/net/netlink.h:991 [inline]
 genlmsg_new include/net/genetlink.h:431 [inline]
 ovs_dp_cmd_alloc_info net/openvswitch/datapath.c:1595 [inline]
 ovs_dp_cmd_del+0x64/0x360 net/openvswitch/datapath.c:1909
 genl_family_rcv_msg_doit+0x22e/0x320 net/netlink/genetlink.c:756
 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
 genl_rcv_msg+0x5f2/0x780 net/netlink/genetlink.c:850
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4a1d18eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4a1e0b2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4a1d3e5fa0 RCX: 00007f4a1d18eec9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f4a1d211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a1d3e6038 R14: 00007f4a1d3e5fa0 R15: 00007ffd0d732328
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/05 15:40 linux-6.1.y 882efbdd9d34 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sendmsg
2025/09/15 11:19 linux-6.1.y 3db754f56897 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sendmsg
2025/09/09 11:16 linux-6.1.y 28c695c365e1 d291dd2d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sendmsg
2025/07/31 15:32 linux-6.1.y 3594f306da12 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sendmsg
2025/06/23 07:42 linux-6.1.y 58485ff1a74f d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sendmsg
* Struck through repros no longer work on HEAD.