[v6.1] INFO: rcu detected stall in sendmsg (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 58485ff1a74f Linux 6.1.141
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1175db0c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c186557a18643a0b
dashboard link: https://syzkaller.appspot.com/bug?extid=ddb3e33c76ab8ecb85a3
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/50f937e6976c/disk-58485ff1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/32fbd75d9fae/vmlinux-58485ff1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/56b5a2c82bda/bzImage-58485ff1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ddb3e3...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2690 jiffies s: 1773 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4405 Comm: syz.4.5 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4724 [inline]
RIP: 0010:__lock_acquire+0x5eb/0x7c50 kernel/locking/lockdep.c:4999
Code: 07 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 40 82 8b 90 be 08 00 00 00 e8 3d 5b 6f 00 48 0f a3 1d b5 8c 28 0f <73> 1a 48 8d 04 5b c1 e0 06 48 8d 98 00 01 24 90 49 b8 00 00 00 00
RSP: 0018:ffffc900001dfec0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000015 RCX: ffffffff8162f583
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff908b8240
RBP: ffffc900001e0110 R08: dffffc0000000000 R09: fffffbfff2117049
R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: ffff88807a15bb80
R13: 0000000000000000 R14: 0000000000000002 R15: ffff88807a15c770
FS: 00007fe9528486c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30801ff8 CR3: 00000000300ab000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:883 [inline]
pfn_valid include/linux/mmzone.h:1857 [inline]
__virt_addr_valid+0x1a5/0x540 arch/x86/mm/physaddr.c:65
kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:35
__kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471
irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140
rcu_read_unlock_special+0x3c7/0x500 kernel/rcu/tree_plugin.h:675
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:823 [inline]
trace_call_bpf+0x58c/0x680 kernel/trace/bpf_trace.c:137
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9973
perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14
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:682
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 ed 9e 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:ffffc900001e0760 EFLAGS: 00000206
RAX: 2d330e4ababd8800 RBX: 1ffff9200003c0f4 RCX: 2d330e4ababd8800
RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: ffffffff8abf1360
RBP: ffffc900001e0860 R08: dffffc0000000000 R09: fffffbfff2117067
R10: fffffbfff2117067 R11: 1ffffffff2117066 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:823 [inline]
ndisc_send_skb+0xda7/0x1510 net/ipv6/ndisc.c:521
addrconf_rs_timer+0x2b8/0x600 net/ipv6/addrconf.c:3985
call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
expire_timers kernel/time/timer.c:1549 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1820
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
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:orc_find arch/x86/kernel/unwind_orc.c:179 [inline]
RIP: 0010:unwind_next_frame+0x247/0x20b0 arch/x86/kernel/unwind_orc.c:448
Code: dc 77 8e 48 3d 6a 0d 1c 8f 0f 87 a3 17 00 00 45 39 e0 49 bd 00 00 00 00 00 fc ff df 0f 84 7b 01 00 00 4a 8d 34 a5 3c 67 0a 8e <45> 29 e0 4e 8d 64 86 fc 49 89 f7 4c 39 e6 0f 86 c7 10 00 00 49 29
RSP: 0018:ffffc90004bee330 EFLAGS: 00000212
RAX: ffffffff8e80d6ee RBX: ffffc90004bee408 RCX: ffffffff969bf100
RDX: ffffffff8e80d6a0 RSI: ffffffff8e10630c RDI: ffffffff8138551f
RBP: ffffffff816fadd7 R08: 0000000000017f01 R09: 0000000000000000
R10: fffff5200097dc8d R11: 1ffff9200097dc8b R12: 0000000000017ef4
R13: dffffc0000000000 R14: 0000000000006fad R15: dffffc0000000000
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
save_stack+0xf3/0x1e0 mm/page_owner.c:127
__set_page_owner+0x19/0x60 mm/page_owner.c:190
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
__alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
__stack_depot_save+0x35a/0x460 lib/stackdepot.c:474
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x60/0x70 mm/kasan/common.c:52
__kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:328
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:3398 [inline]
slab_alloc mm/slub.c:3406 [inline]
__kmem_cache_alloc_lru mm/slub.c:3413 [inline]
kmem_cache_alloc_lru+0x11a/0x2e0 mm/slub.c:3429
__d_alloc+0x31/0x700 fs/dcache.c:1774
d_alloc fs/dcache.c:1854 [inline]
d_alloc_parallel+0xd9/0x1480 fs/dcache.c:2645
__lookup_slow+0x113/0x3a0 fs/namei.c:1675
lookup_one_len+0x18e/0x2c0 fs/namei.c:2740
start_creating+0x184/0x310 fs/debugfs/inode.c:377
__debugfs_create_file+0x6f/0x510 fs/debugfs/inode.c:422
debugfs_hw_add+0xed/0x3a0 net/mac80211/debugfs.c:653
ieee80211_register_hw+0x2c45/0x38c0 net/mac80211/main.c:1391
mac80211_hwsim_new_radio+0x28c2/0x4c40 drivers/net/wireless/mac80211_hwsim.c:4582
hwsim_new_radio_nl+0xafa/0xce0 drivers/net/wireless/mac80211_hwsim.c:5176
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:2493
genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
netlink_unicast+0x74c/0x8c0 net/netlink/af_netlink.c:1337
netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1859
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: 0033:0x7fe95198e929
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:00007fe952848038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe951bb5fa0 RCX: 00007fe95198e929
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 000000000000000e
RBP: 00007fe951a10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe951bb5fa0 R15: 00007ffdfe49b398
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 28c695c365e1 Linux 6.1.150
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12dfd562580000
kernel config: https://syzkaller.appspot.com/x/.config?x=cc3aff322420b627
dashboard link: https://syzkaller.appspot.com/bug?extid=ddb3e33c76ab8ecb85a3
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10998b12580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/469ee0d9feec/disk-28c695c3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0df88732ae21/vmlinux-28c695c3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/192a7b0e5295/bzImage-28c695c3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ddb3e3...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2691 jiffies s: 14409 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: 9733 Comm: syz.1.4803 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:folio_test_slab include/linux/page-flags.h:487 [inline]
RIP: 0010:virt_to_slab mm/slab.h:177 [inline]
RIP: 0010:kasan_addr_to_slab+0x44/0xc0 mm/kasan/common.c:36
Code: 83 e0 c0 48 ba 00 00 00 00 00 ea ff ff 48 8b 4c 10 08 f6 c1 01 75 7a 48 01 d0 66 90 48 8b 48 08 f6 c1 01 75 42 66 90 48 8b 08 <48> c1 e1 36 48 c1 f9 3f 48 21 c1 48 89 c8 5b c3 31 c0 5b c3 48 89
RSP: 0018:ffffc90000007458 EFLAGS: 00000046
RAX: ffffea0002e38ec0 RBX: ffff8880b8e3b970 RCX: 00fff00000001000
RDX: ffffea0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c3ee4e
R10: fffffbfff1c3ee4e R11: 1ffffffff1c3ee4d R12: 0000000000000000
R13: dffffc0000000001 R14: ffff8880b8e3b970 R15: ffff8880b8e3b978
FS: 000055556f3b8500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f46589955d8 CR3: 000000006a451000 CR4: 00000000003506f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>

__kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471
irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140

rcu_read_unlock_special+0x3c7/0x500 kernel/rcu/tree_plugin.h:678

__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:823 [inline]

__perf_event_output kernel/events/core.c:7741 [inline]
perf_event_output_forward+0x237/0x2a0 kernel/events/core.c:7750
__perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
perf_tp_event+0x335/0xb60 kernel/events/core.c:10029
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10002

perf_trace_preemptirq_template+0x287/0x330 include/trace/events/preemptirq.h:14
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 5d 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:ffffc90000007c20 EFLAGS: 00000206
RAX: bd2495a849a89700 RBX: 1ffff92000000f8c RCX: bd2495a849a89700
RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: ffffffff8adefae0
RBP: ffffc90000007d08 R08: dffffc0000000000 R09: fffffbfff215c460
R10: fffffbfff215c460 R11: 1ffffffff215c45f 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]

rebalance_domains+0x89c/0x9d0 kernel/sched/fair.c:11044

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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 0e c2 65 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c6 4b 36 f7 65 8b 05 e7 04 e1 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90005fa7520 EFLAGS: 00000206
RAX: bd2495a849a89700 RBX: 0000000000000a02 RCX: bd2495a849a89700
RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: 0000000000000001
RBP: ffffc90005fa75b8 R08: dffffc0000000000 R09: fffffbfff215c460
R10: fffffbfff215c460 R11: 1ffffffff215c45f R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff96ec1bd8 R15: 1ffff92000bf4ea4
debug_object_activate+0x2d7/0x490 lib/debugobjects.c:716
debug_rcu_head_queue kernel/rcu/rcu.h:190 [inline]
kvfree_call_rcu+0xb3/0x870 kernel/rcu/tree.c:3396
sctp_transport_destroy net/sctp/transport.c:171 [inline]
sctp_transport_put+0xb3/0x140 net/sctp/transport.c:486
sctp_backlog_rcv+0x1b2/0x3e0 net/sctp/input.c:353
sk_backlog_rcv include/net/sock.h:1119 [inline]
__release_sock+0x1b9/0x420 net/core/sock.c:2939
release_sock+0x5b/0x1b0 net/core/sock.c:3503
sctp_sendmsg+0x1c17/0x2980 net/sctp/socket.c:2035

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: 0033:0x7ff51b18ebe9

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:00007fff5c11f878 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff51b3c5fa0 RCX: 00007ff51b18ebe9
RDX: 0000000000000041 RSI: 0000200000000600 RDI: 0000000000000004
RBP: 00007ff51b211e19 R08: 0000000000000000 R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000

R13: 00007ff51b3c5fa0 R14: 00007ff51b3c5fa0 R15: 0000000000000003
</TASK>


---
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