syzbot


INFO: rcu detected stall in sctp_setsockopt (2)

Status: upstream: reported on 2026/05/28 16:14
Reported-by: syzbot+75f61b34664ddb3f1cd0@syzkaller.appspotmail.com
First crash: 12d, last: 12d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in sctp_setsockopt 1 1 596d 596d 0/3 auto-obsoleted due to no activity on 2025/01/29 14:06
upstream INFO: rcu detected stall in sctp_setsockopt net 1 8 2462d 2668d 0/29 auto-closed as invalid on 2019/12/12 00:34
linux-4.19 INFO: rcu detected stall in sctp_setsockopt 1 3 2140d 2187d 0/1 auto-closed as invalid on 2020/11/28 08:55
upstream INFO: rcu detected stall in sctp_setsockopt (2) sctp 1 8 2109d 2248d 0/29 auto-closed as invalid on 2020/11/28 11:26
linux-6.1 INFO: rcu detected stall in sctp_setsockopt 1 1 38d 38d 0/3 upstream: reported on 2026/05/02 14:43

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (0 ticks this GP) idle=0fb/1/0x4000000000000000 softirq=34341/34341 fqs=2099 
	(detected by 1, t=10502 jiffies, g=40989, q=1170)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 12987 Comm: syz.2.3245 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:check_preemption_disabled+0x6/0x110 lib/smp_processor_id.c:13
Code: f2 32 8a e8 2c 01 00 00 65 ff 0d c1 6a 46 76 5b c3 00 00 cc 48 c7 c7 a0 06 7a 8a 48 c7 c6 e0 06 7a 8a eb 00 55 41 57 41 56 53 <48> 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05 79
RSP: 0018:ffffc90000007918 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 1ffff92000000f2c RCX: f8f8f8f8f8f8f8f8
RDX: 0000000000000100 RSI: ffffffff8a7a06e0 RDI: ffffffff8a7a06a0
RBP: ffffc90000007a08 R08: ffffffff8d89f82f R09: 1ffffffff1b13f05
R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000802
FS:  00007f47f9f326c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c17ff8 CR3: 0000000063290000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_nmi_exit+0xa/0xf0 kernel/rcu/tree.c:744
 rcu_irq_exit_irqson+0x92/0x120 kernel/rcu/tree.c:841
 trace_irq_enable_rcuidle+0x11e/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 df 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90000007b00 EFLAGS: 00000206
RAX: f833e38fbf134d00 RBX: 1ffff92000000f64 RCX: f833e38fbf134d00
RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700
RBP: ffffc90000007bd8 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8c323800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:refill_stock+0x344/0x540 mm/memcontrol.c:2283
Code: 00 00 9c 8f 44 24 60 f7 44 24 60 00 02 00 00 41 c6 44 1e 04 f8 75 46 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <49> c7 04 1e 00 00 00 00 41 c7 44 1e 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000301f880 EFLAGS: 00000206
RAX: f833e38fbf134d00 RBX: dffffc0000000000 RCX: f833e38fbf134d00
RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700
RBP: ffffc9000301f970 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000001
R13: ffff8880b9036498 R14: 1ffff92000603f18 R15: 0000000000000a06
 obj_cgroup_uncharge_pages mm/memcontrol.c:2996 [inline]
 refill_obj_stock+0x25c/0x470 mm/memcontrol.c:3259
 memcg_slab_free_hook+0x157/0x1f0 mm/slab.h:364
 do_slab_free mm/slub.c:3437 [inline]
 ___cache_free+0x63/0x120 mm/slub.c:3511
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 __kmalloc_track_caller+0x125/0x330 mm/slub.c:4930
 memdup_sockptr include/linux/sockptr.h:74 [inline]
 sctp_setsockopt+0x7d/0xf80 net/sctp/socket.c:4588
 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2212
 __do_sys_setsockopt net/socket.c:2223 [inline]
 __se_sys_setsockopt net/socket.c:2220 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f47fbcd8e59
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:00007f47f9f32028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f47fbf51fa0 RCX: 00007f47fbcd8e59
RDX: 0000000000000078 RSI: 0000000000000084 RDI: 000000000000000e
RBP: 00007f47fbd6ed6f R08: 0000000000000004 R09: 0000000000000000
R10: 0000200000000040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47fbf52038 R14: 00007f47fbf51fa0 R15: 00007ffcc25d8068
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/28 16:13 linux-5.15.y 241d66fa280c 681715f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sctp_setsockopt
* Struck through repros no longer work on HEAD.