INFO: rcu detected stall in sys_setsockopt

Status: upstream: reported on 2026/02/13 08:47
Reported-by: syzbot+035e355f20769f1e35a0@syzkaller.appspotmail.com
First crash: 186d, last: 15d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_setsockopt (2) kvm 1 2 1846d 1888d 0/29 auto-closed as invalid on 2021/10/27 00:02
upstream INFO: rcu detected stall in sys_setsockopt kvm 1 1 2008d 2008d 0/29 auto-closed as invalid on 2021/05/17 17:51
upstream INFO: rcu detected stall in sys_setsockopt (4) prio:high mm 1 syz, C done inconclusive 108 8h28m 631d 0/29 upstream: reported C repro on 2024/11/25 08:53
upstream INFO: rcu detected stall in sys_setsockopt (3) net 1 4 1719d 1745d 0/29 closed as invalid on 2022/02/08 10:00
linux-4.19 BUG: soft lockup in sys_setsockopt 1 3 1941d 1969d 0/1 auto-closed as invalid on 2021/08/23 07:10

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10500 ticks this GP) idle=1b34/1/0x4000000000000000 softirq=12978/12978 fqs=3799
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1198436          0            0
rcu: 	cputime:    19623      32865           46   ==> 52490(ms)
rcu: 	(t=10500 jiffies g=11521 q=2360 ncpus=2)
CPU: 0 PID: 6155 Comm: syz.3.88 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:seqcount_lockdep_reader_access+0x19a/0x1d0 include/linux/seqlock.h:105
Code: 00 4d 85 e4 75 16 e8 d5 c6 0f 00 eb 15 e8 ce c6 0f 00 e8 29 1d 15 09 4d 85 e4 74 ea e8 bf c6 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc900000069c0 EFLAGS: 00000246
RAX: ffffffff8177a861 RBX: 0000000000000000 RCX: ffff888023935a00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000006a78 R08: ffffffff911eb5ff R09: 1ffffffff223d6bf
R10: dffffc0000000000 R11: fffffbfff223d6c0 R12: 0000000000000200
R13: 000001fb63109b96 R14: 1ffff92000000d38 R15: dffffc0000000000
FS:  00007faf002eb6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001a00 CR3: 000000002f97a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000b6e DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 ktime_get_with_offset+0x94/0x330 kernel/time/timekeeping.c:889
 ktime_get_real include/linux/timekeeping.h:79 [inline]
 netif_rx_internal+0x33d/0x4e0 net/core/dev.c:5153
 __netif_rx+0x78/0xc0 net/core/dev.c:5196
 loopback_xmit+0x438/0x650 drivers/net/loopback.c:89
 __netdev_start_xmit include/linux/netdevice.h:4945 [inline]
 netdev_start_xmit include/linux/netdevice.h:4959 [inline]
 xmit_one net/core/dev.c:3644 [inline]
 dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660
 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454
 dev_queue_xmit include/linux/netdevice.h:3115 [inline]
 neigh_hh_output include/net/neighbour.h:527 [inline]
 neigh_output include/net/neighbour.h:541 [inline]
 ip_finish_output2+0xd4f/0x1260 net/ipv4/ip_output.c:235
 NF_HOOK_COND include/linux/netfilter.h:293 [inline]
 ip_output+0x2a5/0x3a0 net/ipv4/ip_output.c:436
 iptunnel_xmit+0x4d0/0x910 net/ipv4/ip_tunnel_core.c:82
 udp_tunnel_xmit_skb+0x22f/0x380 net/ipv4/udp_tunnel_core.c:172
 geneve_xmit_skb drivers/net/geneve.c:1007 [inline]
 geneve_xmit+0x26c3/0x3530 drivers/net/geneve.c:1120
 __netdev_start_xmit include/linux/netdevice.h:4945 [inline]
 netdev_start_xmit include/linux/netdevice.h:4959 [inline]
 xmit_one net/core/dev.c:3644 [inline]
 dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660
 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454
 neigh_output include/net/neighbour.h:543 [inline]
 ip6_finish_output2+0xe2e/0x1620 net/ipv6/ip6_output.c:141
 dst_output include/net/dst.h:467 [inline]
 NF_HOOK include/linux/netfilter.h:304 [inline]
 ndisc_send_skb+0xbb9/0x1480 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4036
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_count_add+0x42/0x1a0 kernel/sched/core.c:5850
Code: 2f 97 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 eb 00 00 00 83 3d 0e 3c d2 15 00 75 07 65 8b 05 cd cf a6 7e 65 01 3d c6 cf a6 7e <48> c7 c0 80 24 2f 97 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e6 00
RSP: 0018:ffffc9000babf8f8 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 1ffff92001757f3d RCX: ffffffff972f2403
RDX: ffff888023935a00 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffc9000babfab0 R09: 0000000000000001
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000babfd60
R13: ffffc9000babf9e8 R14: ffffc9000babfa20 R15: dffffc0000000000
 unwind_next_frame+0xb7/0x2990 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 sctp_setsockopt+0xb00/0x11e0 net/sctp/socket.c:4794
 do_sock_setsockopt+0x175/0x1a0 net/socket.c:2322
 __sys_setsockopt net/socket.c:2345 [inline]
 __do_sys_setsockopt net/socket.c:2354 [inline]
 __se_sys_setsockopt net/socket.c:2351 [inline]
 __x64_sys_setsockopt+0x182/0x200 net/socket.c:2351
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7faeff39e019
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:00007faf002eb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007faeff625fa0 RCX: 00007faeff39e019
RDX: 000000000000000d RSI: 0000000000000084 RDI: 0000000000000005
RBP: 00007faeff43500c R08: 0000000000000008 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faeff626038 R14: 00007faeff625fa0 R15: 00007fff01fe63b8
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/03 05:22 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_setsockopt
2026/06/24 15:42 linux-6.6.y d1cfde2d5d15 302586aa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_setsockopt
2026/05/21 03:26 linux-6.6.y eac8889a3a1c 41b8c833 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in sys_setsockopt
2026/02/13 08:46 linux-6.6.y 1b4ef5214f17 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_setsockopt
* Struck through repros no longer work on HEAD.