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INFO: rcu detected stall in inet_dgram_connect (2)

Status: auto-obsoleted due to no activity on 2026/06/02 00:06
Subsystems: net
Labels: prio:normal
[Documentation on labels]
First crash: 104d, last: 104d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
1be67579-0f59-4155-b459-a05e272e3aac assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in inet_dgram_connect (2) 2026/05/22 02:08 2026/05/22 02:08 2026/05/22 02:49 d57425845dbe663f86e1e54a4997e95bd557b624
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: rcu detected stall in inet_dgram_connect 1 1 2538d 2538d 0/3 auto-closed as invalid on 2019/11/01 21:16
upstream INFO: rcu detected stall in inet_dgram_connect net 1 22 2694d 2723d 0/29 auto-closed as invalid on 2019/07/28 11:58

Sample crash report:
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P16922/2:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=111425, q=1414 ncpus=1)
task:syz.0.3880      state:R  running task     stack:27560 pid:16922 tgid:16921 ppid:5823   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x6120 kernel/sched/core.c:6908
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235
 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5864 [inline]
RIP: 0010:lock_acquire+0x17f/0x380 kernel/locking/lockdep.c:5825
Code: 00 65 8b 05 eb 0f 29 12 85 c0 0f 85 ae 00 00 00 65 48 8b 05 6b c8 28 12 8b 90 54 0b 00 00 85 d2 0f 85 98 00 00 00 9c 8f 04 24 <fa> 48 c7 c7 ff d0 f6 8d e8 44 fd a8 09 45 89 e8 44 89 e1 89 da 65
RSP: 0018:ffffc90004faf590 EFLAGS: 00000246
RAX: ffff8880314b1e80 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81b7aaf1 RDI: fffffbfff1cfd244
RBP: ffffffff8e7e9220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 000000000000b7cb R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:773
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4515 [inline]
 slab_alloc_node mm/slub.c:4844 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4851
 dst_alloc+0x99/0x1a0 net/core/dst.c:90
 rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1651
 __mkroute_output net/ipv4/route.c:2655 [inline]
 ip_route_output_key_hash_rcu+0x87a/0x2870 net/ipv4/route.c:2875
 ip_route_output_key_hash+0x118/0x2b0 net/ipv4/route.c:2705
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2932
 ip_route_connect include/net/route.h:355 [inline]
 __ip4_datagram_connect+0x8bf/0x1470 net/ipv4/datagram.c:49
 ip4_datagram_connect+0x2e/0x50 net/ipv4/datagram.c:92
 inet_dgram_connect+0x143/0x200 net/ipv4/af_inet.c:594
 __sys_connect_file+0x141/0x1a0 net/socket.c:2089
 __sys_connect+0x141/0x170 net/socket.c:2108
 __do_sys_connect net/socket.c:2114 [inline]
 __se_sys_connect net/socket.c:2111 [inline]
 __x64_sys_connect+0x72/0xb0 net/socket.c:2111
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd705d9c799
RSP: 002b:00007fd706d02028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007fd706015fa0 RCX: 00007fd705d9c799
RDX: 0000000000000054 RSI: 0000200000000080 RDI: 0000000000000003
RBP: 00007fd705e32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd706016038 R14: 00007fd706015fa0 R15: 00007ffde5b0e788
 </TASK>
net_ratelimit: 10887 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:2e:a7:5a:76:f8, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 11490 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:2e:a7:5a:76:f8, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:fe:2e:a7:5a:76:f8, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/03 23:56 upstream 0031c06807cf 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in inet_dgram_connect
* Struck through repros no longer work on HEAD.