[v6.1] INFO: rcu detected stall in sctp_setsockopt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4931e0e1673d Linux 6.1.170
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11527ece580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=6b38054ec1597807e8ce
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cd62baf6f839/disk-4931e0e1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/28b9d34fdc6c/vmlinux-4931e0e1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5056ec0ca104/bzImage-4931e0e1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6b3805...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2675 jiffies s: 37793 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: 10936 Comm: syz.4.2005 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__memset+0x0/0x30 arch/x86/lib/memset_64.S:27
Code: 66 44 8b 1e 66 44 8b 54 16 fe 66 44 89 1f 66 44 89 54 17 fe eb 0c 48 83 fa 01 72 06 44 8a 1e 44 88 1f c3 48 89 d1 f3 a4 c3 00 <eb> 2e 0f 1f 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6
RSP: 0018:ffffc90000007938 EFLAGS: 00000002
RAX: 1ffff92000000f01 RBX: ffffc900000079c0 RCX: ffffffff81a5a4b2
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000007b00
RBP: ffffc90000007ba8 R08: ffffc90000007b0f R09: 1ffff92000000f61
R10: dffffc0000000000 R11: fffff52000000f62 R12: dffffc0000000000
R13: 0000000000000014 R14: ffffe8ffff6044c0 R15: ffffc90000007b00
FS: 00007fb4f6d3e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c394a5c CR3: 0000000026f3f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
perf_tp_event+0x1b2/0xc30 kernel/events/core.c:10050
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032
perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
trace_irq_disable include/trace/events/preemptirq.h:36 [inline]
trace_hardirqs_off_finish+0x13f/0x180 kernel/trace/trace_preemptirq.c:67
irqentry_enter+0x33/0x50 kernel/entry/common.c:382
sysvec_irq_work+0xa/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:handle_softirqs+0x1c8/0x930 kernel/softirq.c:584
Code: 89 7c 24 44 0f b7 db 48 c7 c7 00 07 8b 8a e8 bf 90 de 08 65 66 c7 05 a5 35 b4 7e 00 00 e8 80 73 39 00 fb 49 c7 c6 c0 a0 80 8c <89> 5c 24 4c b8 ff ff ff ff 0f bc 44 24 4c 41 89 c5 41 ff c5 0f 84
RSP: 0018:ffffc90000007e00 EFLAGS: 00000286
RAX: ab0cde81ba656300 RBX: 0000000000000200 RCX: ab0cde81ba656300
RDX: dffffc0000000000 RSI: ffffffff8a8c1120 RDI: ffffffff8adf1320
RBP: ffffc90000007f30 R08: ffff8880b8e3580b R09: 1ffff110171c6b01
R10: dffffc0000000000 R11: ffffed10171c6b02 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff8c80a0c0 R15: 000000000000000a
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 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:rcu_read_unlock_special+0x1/0x510 kernel/rcu/tree_plugin.h:630
Code: 46 66 00 eb b0 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 94 49 89 fd 4c 89 f7 e8 8c 46 66 00 4c 89 ef eb 84 0f 1f 80 00 00 00 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00
RSP: 0018:ffffc9000d317b10 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff88807c62bfbc RCX: 0000000000080000
RDX: ffffc9000e349000 RSI: 0000000000017dc3 RDI: ffff88807c62bb80
RBP: dffffc0000000000 R08: ffff88801c1711ff R09: 1ffff1100382e23f
R10: dffffc0000000000 R11: ffffed100382e240 R12: 1ffff1100f8c57f7
R13: 0000000000000003 R14: ffff88807c62bfc0 R15: dffffc0000000000
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:823 [inline]
page_ext_put+0x91/0xb0 mm/page_ext.c:182
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1486 [inline]
free_pcp_prepare mm/page_alloc.c:1536 [inline]
free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508
free_slab mm/slub.c:2036 [inline]
discard_slab mm/slub.c:2042 [inline]
__unfreeze_partials+0x1a5/0x200 mm/slub.c:2591
put_cpu_partial+0x17c/0x250 mm/slub.c:2667
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
slab_alloc_node mm/slub.c:3359 [inline]
__kmem_cache_alloc_node+0x140/0x260 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956
memdup_sockptr include/linux/sockptr.h:101 [inline]
sctp_setsockopt+0x86/0xf90 net/sctp/socket.c:4592
__sys_setsockopt+0x2bf/0x3d0 net/socket.c:2287
__do_sys_setsockopt net/socket.c:2298 [inline]
__se_sys_setsockopt net/socket.c:2295 [inline]
__x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2295
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb4f5d9cdd9
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:00007fb4f6d3e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fb4f6015fa0 RCX: 00007fb4f5d9cdd9
RDX: 000000000000000b RSI: 0000000000000084 RDI: 0000000000000005
RBP: 00007fb4f5e32d69 R08: 000000000000000e R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb4f6016038 R14: 00007fb4f6015fa0 R15: 00007ffdcf5550b8
</TASK>


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