INFO: rcu detected stall in inet_diag_dump_compat

Status: upstream: reported on 2026/06/11 10:06
Reported-by: syzbot+e4f88e317b26fe8b03db@syzkaller.appspotmail.com
First crash: 57d, last: 57d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in inet_diag_dump_compat (2) 1 2 23d 93d 0/3 upstream: reported on 2026/05/07 06:46
linux-5.15 INFO: rcu detected stall in inet_diag_dump_compat 1 1 310d 310d 0/3 auto-obsoleted due to no activity on 2026/01/10 04:49
upstream BUG: soft lockup in inet_diag_dump_compat mm 1 1 428d 428d 0/29 closed as invalid on 2025/07/11 15:16

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2641 jiffies s: 134965 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: 32398 Comm: syz.1.9093 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_is_held_type+0x61/0x190 kernel/locking/lockdep.c:5701
Code: 0f 85 f4 00 00 00 65 48 8b 1d 3b 16 d3 75 83 bb dc 0a 00 00 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c <8f> 04 24 4c 8b 2c 24 fa 48 c7 c7 80 27 8c 8a e8 eb 12 00 00 65 ff
RSP: 0018:ffffc900001e0750 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88801aa8da00 RCX: 6a0b76f8fb5f2c00
RDX: ffff88801aa8da00 RSI: 00000000ffffffff RDI: ffffffff8cb2de60
RBP: 00000000ffffffff R08: dffffc0000000000 R09: 1ffffffff215fe48
R10: dffffc0000000000 R11: fffffbfff215fe49 R12: ffffffff8cb805e0
R13: 1ffff9200003c100 R14: ffffffff8cb2de60 R15: 00000000ffffffff
FS:  00007f17da5f66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f63cf577ff8 CR3: 000000001df42000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 bpf_prog_run_array include/linux/bpf.h:1658 [inline]
 trace_call_bpf+0x1f2/0x6b0 kernel/trace/bpf_trace.c:135
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
 perf_trace_preemptirq_template+0x268/0x320 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+0x7f/0x510 kernel/rcu/tree_plugin.h:685
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 82 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e0ac0 EFLAGS: 00000206
RAX: 6a0b76f8fb5f2c00 RBX: 1ffff9200003c160 RCX: 6a0b76f8fb5f2c00
RDX: dffffc0000000000 RSI: ffffffff8a8c1aa0 RDI: ffffffff8adf2060
RBP: ffffc900001e0bb0 R08: ffffffff90aff2cf R09: 1ffffffff215fe59
R10: dffffc0000000000 R11: fffffbfff215fe5a 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]
 ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2147
 __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 __hrtimer_run_queues+0x54a/0xd50 kernel/time/hrtimer.c:1815
 hrtimer_run_softirq+0x183/0x2a0 kernel/time/hrtimer.c:1832
 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596
 __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:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90003536e60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 6a0b76f8fb5f2c00
RDX: 0000000000000000 RSI: ffffffff8a8c2c20 RDI: ffffffff8adf2060
RBP: ffffc90003536f78 R08: dffffc0000000000 R09: 1ffffffff215fe59
R10: dffffc0000000000 R11: fffffbfff215fe5a R12: 0000000000000001
R13: 1ffff920006a6dd8 R14: 0000000000000246 R15: dffffc0000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 inet_diag_dump_icsk+0x372/0x14c0 net/ipv4/inet_diag.c:1038
 __inet_diag_dump+0x1f6/0x380 net/ipv4/inet_diag.c:1179
 inet_diag_dump_compat+0x17e/0x220 net/ipv4/inet_diag.c:1288
 netlink_dump+0x6a3/0xd00 net/netlink/af_netlink.c:2236
 __netlink_dump_start+0x537/0x6f0 net/netlink/af_netlink.c:2338
 netlink_dump_start include/linux/netlink.h:269 [inline]
 inet_diag_rcv_msg_compat+0x207/0x420 net/ipv4/inet_diag.c:1323
 sock_diag_rcv_msg+0x3cc/0x5f0 net/core/sock_diag.c:-1
 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511
 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:295
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5be/0x970 net/socket.c:2518
 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572
 __sys_sendmsg net/socket.c:2601 [inline]
 __do_sys_sendmsg net/socket.c:2610 [inline]
 __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608
 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: 0033:0x7f17dc39ce59
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:00007f17da5f6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f17dc615fa0 RCX: 00007f17dc39ce59
RDX: 0000000000044010 RSI: 0000200000000180 RDI: 000000000000000f
RBP: 00007f17dc432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f17dc616038 R14: 00007f17dc615fa0 R15: 00007ffe3a20acb8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/11 10:05 linux-6.1.y 228da13e907e b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in inet_diag_dump_compat
* Struck through repros no longer work on HEAD.