BUG: soft lockup in tcp_tasklet_func (2)

Status: auto-obsoleted due to no activity on 2026/01/22 11:08
Reported-by: syzbot+e3ad930a30bb8d33058f@syzkaller.appspotmail.com
First crash: 294d, last: 294d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 BUG: soft lockup in tcp_tasklet_func 1 1 412d 412d 0/2 auto-obsoleted due to no activity on 2025/09/26 12:22
android-5-15 BUG: soft lockup in tcp_tasklet_func 1 1 775d 775d 0/2 auto-obsoleted due to no activity on 2024/09/27 22:34
linux-5.15 INFO: rcu detected stall in tcp_tasklet_func 1 1 17d 17d 0/3 upstream: reported on 2026/07/27 23:06

Sample crash report:
RBP: 0000000000000003 R08: 00007ffd6f96479c R09: 0079746972756365
R10: 00007ffd6f964800 R11: 0000000000000216 R12: 00007efd2b7b6960
R13: 00007ffd6f96479c R14: 0000000000000000 R15: 00007efd2b7b7020
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 246s! [syz-executor:14198]
Modules linked in:
CPU: 0 PID: 14198 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0xf2/0x140 arch/x86/kernel/kvm.c:1064
Code: 96 13 04 f4 eb 9a fa 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 3f 0f b6 07 40 38 f0 75 10 66 90 0f 00 2d 20 96 13 04 fb f4 <e9> 71 ff ff ff fb e9 6b ff ff ff e8 ae c9 b8 03 89 f9 80 e1 07 38
RSP: 0018:ffffc90000007b60 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff888120070098 RCX: ffffffff84f43dc2
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff888120070098
RBP: ffffc90000007bf0 R08: dffffc0000000000 R09: ffffed102400e014
R10: ffffed102400e014 R11: 1ffff1102400e013 R12: 1ffff1103ee00001
R13: ffff8881f7038cd4 R14: dffffc0000000000 R15: 1ffff92000000f6c
FS:  0000555573def500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6e19f2194 CR3: 00000001233e8000 CR4: 00000000003506b0
Call Trace:
 <IRQ>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x690/0xc40 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
 _raw_spin_lock+0xd8/0xe0 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 tcp_tsq_handler+0x22/0x150 net/ipv4/tcp_output.c:1032
 tcp_tasklet_func+0x339/0x3c0 net/ipv4/tcp_output.c:1066
 tasklet_action_common+0x22e/0x630 kernel/softirq.c:878
 tasklet_action+0x4c/0x60 kernel/softirq.c:903
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 __do_softirq kernel/softirq.c:680 [inline]
 invoke_softirq kernel/softirq.c:497 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
 common_interrupt+0xbe/0xe0 arch/x86/kernel/irq.c:242
 </IRQ>
 <TASK>
 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215
Code: 8b 3d 1c 53 02 06 48 89 de e8 b4 b6 43 00 5b 5d c3 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 55 48 89 e5 48 8b 45 08 <65> 48 8b 0d 90 4f 92 7e 65 8b 15 91 4f 92 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000977840 EFLAGS: 00000246
RAX: ffffffff8135f98e RBX: 000000011a229968 RCX: ffff88812810bcc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000977840 R08: ffff88812810bcc0 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000004 R14: 000000000000002e R15: 0000000000000000
 __virt_addr_valid+0xce/0x2e0 arch/x86/mm/physaddr.c:61
 check_heap_object mm/usercopy.c:188 [inline]
 __check_object_size+0x100/0x600 mm/usercopy.c:250
 check_object_size include/linux/thread_info.h:199 [inline]
 check_copy_size include/linux/thread_info.h:235 [inline]
 copy_to_user include/linux/uaccess.h:168 [inline]
 xt_data_to_user net/netfilter/x_tables.c:316 [inline]
 xt_target_to_user+0x219/0x380 net/netfilter/x_tables.c:344
 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:861 [inline]
 get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline]
 do_ipt_get_ctl+0xcd4/0x10e0 net/ipv4/netfilter/ip_tables.c:1670
 nf_getsockopt+0x27f/0x2a0 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x148/0x1d0 net/ipv4/ip_sockglue.c:1826
 tcp_getsockopt+0xff/0x130 net/ipv4/tcp.c:4453
 sock_common_getsockopt+0xaa/0xc0 net/core/sock.c:3671
 __sys_getsockopt+0x215/0x4a0 net/socket.c:2322
 __do_sys_getsockopt net/socket.c:2337 [inline]
 __se_sys_getsockopt net/socket.c:2334 [inline]
 __x64_sys_getsockopt+0xbf/0xd0 net/socket.c:2334
 x64_sys_call+0x3d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:56
 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: 0033:0x7efd2b590d0a
Code: ff c3 66 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7
RSP: 002b:00007ffd6f964778 EFLAGS: 00000216 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007ffd6f964800 RCX: 00007efd2b590d0a
RDX: 0000000000000041 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007ffd6f96479c R09: 0079746972756365
R10: 00007ffd6f964800 R11: 0000000000000216 R12: 00007efd2b7b6960
R13: 00007ffd6f96479c R14: 0000000000000000 R15: 00007efd2b7b7020
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 14779 Comm: syz.6.3640 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:native_halt arch/x86/include/asm/irqflags.h:57 [inline]
RIP: 0010:halt arch/x86/include/asm/irqflags.h:98 [inline]
RIP: 0010:kvm_wait+0xcc/0x140 arch/x86/kernel/kvm.c:1058
Code: 20 f6 44 24 21 02 75 24 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 48 0f b6 07 40 38 f0 75 a6 66 90 0f 00 2d 45 96 13 04 f4 <eb> 9a fa 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 3f 0f b6 07
RSP: 0000:ffffc900049ce3a0 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff8881f7127c40 RCX: ffffffff84f43dc2
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8881f7127c40
RBP: ffffc900049ce430 R08: dffffc0000000000 R09: ffffed103ee24f89
R10: ffffed103ee24f89 R11: 1ffff1103ee24f88 R12: 1ffff1103ee20001
R13: ffff8881f7138cd4 R14: dffffc0000000000 R15: 1ffff92000939c74
FS:  00005555749bf500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2a6abd CR3: 00000001320b7000 CR4: 00000000003506a0
DR0: 0000000000009000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x690/0xc40 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock include/linux/spinlock.h:187 [inline]
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0x108/0x110 kernel/locking/spinlock.c:162
 lock_timer_base+0x127/0x270 kernel/time/timer.c:1005
 __mod_timer+0x10a/0xb30 kernel/time/timer.c:1078
 add_timer+0x68/0x80 kernel/time/timer.c:1218
 __queue_delayed_work+0x173/0x200 kernel/workqueue.c:1686
 queue_delayed_work_on+0xdb/0x150 kernel/workqueue.c:1711
 queue_delayed_work include/linux/workqueue.h:525 [inline]
 schedule_delayed_monitor_work kernel/rcu/tree.c:3216 [inline]
 kvfree_call_rcu+0x436/0x7a0 kernel/rcu/tree.c:3472
 trie_delete_elem+0x572/0x720 kernel/bpf/lpm_trie.c:545
 bpf_prog_5186c38a4019a4cb+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline]
 bpf_trace_run3+0x113/0x270 kernel/trace/bpf_trace.c:2323
 __bpf_trace_timer_start+0x2b/0x40 include/trace/events/timer.h:53
 trace_timer_start include/trace/events/timer.h:53 [inline]
 enqueue_timer+0x337/0x480 kernel/time/timer.c:615
 __mod_timer+0x79f/0xb30 kernel/time/timer.c:-1
 mod_timer+0x1f/0x30 kernel/time/timer.c:1172
 sk_reset_timer+0x22/0xb0 net/core/sock.c:3390
 inet_csk_reset_xmit_timer include/net/inet_connection_sock.h:-1 [inline]
 tcp_reset_xmit_timer include/net/tcp.h:1366 [inline]
 tcp_schedule_loss_probe+0x441/0x860 net/ipv4/tcp_output.c:2792
 tcp_set_xmit_timer net/ipv4/tcp_input.c:3272 [inline]
 tcp_ack+0x3939/0x5cd0 net/ipv4/tcp_input.c:3998
 tcp_rcv_established+0x72d/0x1a20 net/ipv4/tcp_input.c:6107
 tcp_v4_do_rcv+0x446/0xa10 net/ipv4/tcp_ipv4.c:1683
 tcp_v4_rcv+0x233c/0x2a80 net/ipv4/tcp_ipv4.c:2114
 ip_protocol_deliver_rcu+0x325/0x6e0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x24e/0x410 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_local_deliver+0x1d8/0x320 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:463 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0x773/0x880 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3da/0x420 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5640 [inline]
 __netif_receive_skb_list_core+0x59e/0x770 net/core/dev.c:5688
 __netif_receive_skb_list net/core/dev.c:5740 [inline]
 netif_receive_skb_list_internal+0x7d2/0xa60 net/core/dev.c:5831
 gro_normal_list include/net/gro.h:433 [inline]
 napi_complete_done+0x36f/0x790 net/core/dev.c:6172
 virtqueue_napi_complete drivers/net/virtio_net.c:403 [inline]
 virtnet_poll+0x991/0x1150 drivers/net/virtio_net.c:1717
 __napi_poll+0xd0/0x5e0 net/core/dev.c:6606
 napi_poll net/core/dev.c:6673 [inline]
 net_rx_action+0x49b/0xaa0 net/core/dev.c:6787
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 __do_softirq kernel/softirq.c:680 [inline]
 invoke_softirq kernel/softirq.c:497 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741
 common_interrupt+0x64/0xe0 arch/x86/kernel/irq.c:242
 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0033:0x7f54c006ef9a
Code: c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 00 c6 44 24 1e 01 48 89 ee 44 89 e7 4c 89 44 24 10 4c 89 54 24 08 e8 36 ea fd ff <4c> 8b 54 24 08 4c 8b 44 24 10 84 c0 0f 85 60 ff ff ff 80 7c 24 1f
RSP: 002b:00007fff7cffe2a0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 00007f54c0f15720 RCX: ffffffff8166bc0e
RDX: 0000000000001c0e RSI: ffffffff8166bc0e RDI: 0000000000000009
RBP: ffffffff8166bc0e R08: 00007f54c03d0000 R09: 00007f54c03d2000
R10: 000000008166bc12 R11: 0000000000000009 R12: 0000000000000009
R13: 0000000000000000 R14: ffffffff8166b4f4 R15: 0000000000000222
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/24 10:59 android14-6.1 22c0b7236c43 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 BUG: soft lockup in tcp_tasklet_func
* Struck through repros no longer work on HEAD.