[v5.15] INFO: rcu detected stall in rtnl_setlink (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=149cf8b4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=3a62d07a7d6f073badae
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3a62d0...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-....: (1 GPs behind) idle=e7b/1/0x4000000000000002 softirq=26081/26082 fqs=5243
(detected by 1, t=10502 jiffies, g=34653, q=1808)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10217 Comm: syz.9.1285 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:strlen+0x3b/0x60 lib/string.c:581
Code: 00 00 00 00 fc ff df 48 89 fb 49 89 c7 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 11 48 ff c3 49 8d 47 01 42 80 7c 3f 01 00 <75> de eb 19 89 d9 80 e1 07 38 c1 7c e6 49 89 fc 48 89 df e8 2d a4
RSP: 0018:ffffc900000070b8 EFLAGS: 00000002
RAX: 0000000000000007 RBX: ffffffff8a0c20a8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8c11c760 RDI: ffffffff8a0c20a0
RBP: ffffc900000071e0 R08: 0000000000000002 R09: 0000000000000000
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: dffffc0000000000
R13: 1ffff92000000e4c R14: dffffc0000000000 R15: 0000000000000006
FS: 00007f64e586a6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feff678e4d0 CR3: 000000007e54a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
trace_event_get_offsets_lock_acquire include/trace/events/lock.h:13 [inline]
perf_trace_lock_acquire+0xb9/0x3c0 include/trace/events/lock.h:13
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x3c6/0x3f0 kernel/locking/lockdep.c:5594
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__perf_output_begin kernel/events/ring_buffer.c:163 [inline]
perf_output_begin_forward+0x97/0xa30 kernel/events/ring_buffer.c:271
__perf_event_output kernel/events/core.c:7804 [inline]
perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7822
__perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 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+0x84/0x480 kernel/rcu/tree_plugin.h:674
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 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: d8184d3ac78d5a00 RBX: 1ffff92000000f60 RCX: d8184d3ac78d5a00
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff7c1b
R10: fffffbfff1ff7c1b R11: 1ffffffff1ff7c1a R12: ffffffff8c120c00
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+0x53d/0xc40 kernel/time/hrtimer.c:1749
hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 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:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
RIP: 0010:rcu_is_watching+0x36/0xa0 kernel/rcu/tree.c:1123
Code: e8 9f cc 45 08 89 c3 83 f8 08 73 5c 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 20 c8 bc 8b 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 c0 82 58 00 48 c7 c3 08 b3 03 00 49 03 1e 48 89
RSP: 0018:ffffc9000304ea00 EFLAGS: 00000246
RAX: 1ffffffff1779904 RBX: 0000000000000000 RCX: d8184d3ac78d5a00
RDX: 0000000000000000 RSI: ffffffff8a59e560 RDI: ffffffff8a59e520
RBP: ffffc9000304eb30 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 0000000000000cc0
R13: dffffc0000000000 R14: ffffffff8bbcc820 R15: dffffc0000000000
trace_lock_release include/trace/events/lock.h:58 [inline]
lock_release+0xba/0x870 kernel/locking/lockdep.c:5634
might_alloc include/linux/sched/mm.h:207 [inline]
slab_pre_alloc_hook+0x27/0xc0 mm/slab.h:492
slab_alloc_node mm/slub.c:3139 [inline]
__kmalloc_node_track_caller+0x68/0x3a0 mm/slub.c:4963
kmalloc_reserve net/core/skbuff.c:356 [inline]
__alloc_skb+0x22c/0x750 net/core/skbuff.c:427
alloc_skb include/linux/skbuff.h:1162 [inline]
nlmsg_new include/net/netlink.h:953 [inline]
rtmsg_ifinfo_build_skb+0x80/0x180 net/core/rtnetlink.c:3886
rtmsg_ifinfo_event net/core/rtnetlink.c:3922 [inline]
rtmsg_ifinfo+0x71/0x120 net/core/rtnetlink.c:3931
netdev_state_change+0xe6/0x140 net/core/dev.c:1442
do_setlink+0x400/0x3980 net/core/rtnetlink.c:3006
rtnl_setlink+0x35b/0x450 net/core/rtnetlink.c:3063
rtnetlink_rcv_msg+0x7ff/0xe90 net/core/rtnetlink.c:5684
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2446
___sys_sendmsg+0x1f0/0x260 net/socket.c:2500
__sys_sendmsg net/socket.c:2529 [inline]
__do_sys_sendmsg net/socket.c:2538 [inline]
__se_sys_sendmsg+0x190/0x250 net/socket.c:2536
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: 0033:0x7f64e7603749
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:00007f64e586a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f64e7859fa0 RCX: 00007f64e7603749
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f64e7687f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64e785a038 R14: 00007f64e7859fa0 R15: 00007ffcbf74efc8
</TASK>


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