INFO: rcu detected stall in packet_rcv (2)

Status: upstream: reported on 2026/11/02 09:41
Reported-by: syzbot+d18ca3099b506be1f906@syzkaller.appspotmail.com
First crash: 11d, last: 11d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in packet_rcv 1 1 18d 18d 0/3 upstream: reported on 2026/10/25 18:19
upstream INFO: rcu detected stall in packet_rcv (2) net 1 1 1053d 1053d 0/29 auto-obsoleted due to no activity on 2024/03/25 03:49
upstream INFO: rcu detected stall in packet_rcv net 1 1 1850d 1850d 0/29 auto-closed as invalid on 2021/12/19 00:49
upstream INFO: rcu detected stall in packet_rcv (3) net bpf 1 4 820d 845d 0/29 auto-obsoleted due to no activity on 2024/11/13 10:03
linux-6.1 INFO: rcu detected stall in packet_rcv 1 1 137d 137d 0/3 auto-obsoleted due to no activity on 2026/10/06 16:32
android-6-1 BUG: soft lockup in packet_rcv 1 1 186d 186d 0/2 auto-obsoleted due to no activity on 2026/08/08 15:43
upstream BUG: soft lockup in packet_rcv perf trace 1 2 319d 372d 0/29 closed as invalid on 2026/02/11 22:39

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 5816 jiffies s: 6733 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: 5144 Comm: syz.1.160 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:lockdep_hardirqs_on_prepare+0xd4/0x7c0 kernel/locking/lockdep.c:4368
Code: 62 98 9e 7e 85 c0 0f 85 b3 03 00 00 48 c7 c0 40 91 c6 97 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 57 05 00 00 83 3d 0c b3 62 16 00 <75> 79 c6 44 13 04 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 f7
RSP: 0018:ffffc900000071e0 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 1ffff92000000e40 RCX: ffffffff97c69103
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff8a600d46
RBP: ffffc90000007290 R08: ffffffff90a57008 R09: ffffffff90a57018
R10: ffffffff90a57010 R11: ffffffff90a57003 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fd6963f66c0(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e586574020 CR3: 000000002827f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
RIP: 0010:rcu_is_watching+0x56/0xa0 kernel/rcu/tree.c:721
Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 d0 78 67 00 48 c7 c3 d8 57 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 2f 8b 03 65 ff 0d 85 1b 96 7e 74 0c 83 e0 04 c1 e8 02 5b
RSP: 0018:ffffc90000007350 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff8880b8c357d8 RCX: 6af172939cf0e700
RDX: ffff888078808000 RSI: ffffffff8afe7280 RDI: ffffffff8afe7240
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff236c448
R10: dffffc0000000000 R11: fffffbfff236c449 R12: 00000000000003b2
R13: dffffc0000000000 R14: ffffffff8c87d980 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:820 [inline]
 is_bpf_text_address+0x200/0x2a0 kernel/bpf/core.c:739
 kernel_text_address+0x9c/0xd0 kernel/extable.c:125
 __kernel_text_address+0x9/0x30 kernel/extable.c:79
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x490 mm/slab.h:742
 slab_alloc_node mm/slub.c:3366 [inline]
 slab_alloc mm/slub.c:3374 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3381 [inline]
 kmem_cache_alloc+0x18b/0x2f0 mm/slub.c:3390
 skb_clone+0x1e7/0x370 net/core/skbuff.c:1663
 packet_rcv+0x5bf/0x1300 net/packet/af_packet.c:2244
 deliver_skb net/core/dev.c:2263 [inline]
 __netif_receive_skb_core+0x686/0x3980 net/core/dev.c:5482
 __netif_receive_skb_one_core net/core/dev.c:5636 [inline]
 __netif_receive_skb+0x74/0x290 net/core/dev.c:5752
 process_backlog+0x37c/0x710 net/core/dev.c:6080
 __napi_poll+0xbb/0x460 net/core/dev.c:6647
 napi_poll net/core/dev.c:6714 [inline]
 net_rx_action+0x622/0xbc0 net/core/dev.c:6828
 handle_softirqs+0x291/0x910 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:migrate_disable+0x0/0x180 kernel/sched/core.c:2227
Code: 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 2d ff ff ff 4c 89 f7 e8 22 c7 7a 00 e9 20 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc9001c7ff038 EFLAGS: 00000282
RAX: ffffffff818c22fa RBX: ffffc9001c7ff0c0 RCX: ffff888078808000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9001c7ff138 R08: dffffc0000000000 R09: 1ffffffff236c448
R10: dffffc0000000000 R11: fffffbfff236c449 R12: ffffffff8d9f9a20
R13: 1ffff920038ffe14 R14: ffff888077580280 R15: 0000000000000000
 bpf_prog_run_array include/linux/bpf.h:1693 [inline]
 trace_call_bpf+0x227/0x6b0 kernel/trace/bpf_trace.c:135
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10018
 perf_trace_lock+0x301/0x390 include/trace/events/lock.h:50
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x8ad/0x920 kernel/locking/lockdep.c:5801
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 zap_pte_range mm/memory.c:1433 [inline]
 zap_pmd_range mm/memory.c:1572 [inline]
 zap_pud_range mm/memory.c:1601 [inline]
 zap_p4d_range mm/memory.c:1622 [inline]
 unmap_page_range+0x1905/0x25b0 mm/memory.c:1643
 unmap_vmas+0x260/0x390 mm/memory.c:1728
 exit_mmap+0x20d/0x970 mm/mmap.c:3293
 __mmput+0x118/0x3a0 kernel/fork.c:1214
 mmput kernel/fork.c:1236 [inline]
 dup_mm kernel/fork.c:1572 [inline]
 copy_mm+0x1465/0x16e0 kernel/fork.c:1605
 copy_process+0x1952/0x4070 kernel/fork.c:2362
 kernel_clone+0x24b/0x900 kernel/fork.c:2769
 __do_sys_clone kernel/fork.c:2910 [inline]
 __se_sys_clone kernel/fork.c:2894 [inline]
 __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2894
 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: 0033:0x7fd69819f559
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:00007fd6963f5fd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fd698425fa0 RCX: 00007fd69819f559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000002c9a4080
RBP: 00007fd698236b50 R08: ffffffffff600000 R09: ffffffffff600000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fd698426038 R14: 00007fd698425fa0 R15: 00007ffd8ea61128
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/02 09:40 linux-6.1.y 08889840163e 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in packet_rcv
* Struck through repros no longer work on HEAD.