syzbot

 sign-in | mailing list | source | docs
🐞 Open [124]
🐞 Fixed [2]
🐞 Invalid [201]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

BUG: soft lockup in sock_read_iter (2)

Status: premoderation: reported on 2025/09/08 00:15
Reported-by: syzbot+1b04d61f70936b1b11dc@syzkaller.appspotmail.com
First crash: 65d, last: 15d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 BUG: soft lockup in sock_read_iter 1 10 452d 583d 0/2 auto-obsoleted due to no activity on 2024/11/14 07:45
android-6-1 BUG: soft lockup in sock_read_iter 1 2 198d 237d 0/2 auto-obsoleted due to no activity on 2025/07/26 10:57
android-5-10 BUG: soft lockup in sock_read_iter 1 2 122d 135d 0/2 auto-obsoleted due to no activity on 2025/10/10 06:20
linux-6.1 INFO: rcu detected stall in sock_read_iter 1 1 300d 300d 0/3 auto-obsoleted due to no activity on 2025/04/25 05:42
upstream INFO: rcu detected stall in sock_read_iter net 1 1 1132d 1132d 0/29 auto-obsoleted due to no activity on 2022/12/05 11:10
upstream INFO: rcu detected stall in sock_read_iter (2) net 1 1 391d 391d 0/29 auto-obsoleted due to no activity on 2025/01/14 23:11

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 225s! [syz-executor:274]
Modules linked in:
CPU: 0 PID: 274 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:ffffc90000e37620 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff88811fff9498 RCX: ffffffff84f43dc2
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff88811fff9498
RBP: ffffc90000e376b0 R08: dffffc0000000000 R09: ffffed1023fff294
R10: ffffed1023fff294 R11: 1ffff11023fff293 R12: 1ffff1103ee00001
R13: ffff8881f7038cd4 R14: dffffc0000000000 R15: 1ffff920001c6ec4
FS:  0000555579742500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa1225156c0 CR3: 00000001215a1000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 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_bh include/linux/spinlock_api_smp.h:127 [inline]
 _raw_spin_lock_bh+0xd8/0xe0 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 lock_sock_nested+0x92/0x280 net/core/sock.c:3507
 lock_sock include/net/sock.h:1769 [inline]
 tcp_recvmsg+0x1f2/0x810 net/ipv4/tcp.c:2697
 inet_recvmsg+0x13b/0x470 net/ipv4/af_inet.c:875
 sock_recvmsg_nosec net/socket.c:1020 [inline]
 sock_recvmsg net/socket.c:1038 [inline]
 sock_read_iter+0x2d3/0x380 net/socket.c:1111
 call_read_iter include/linux/fs.h:2276 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x41e/0x8c0 fs/read_write.c:470
 ksys_read+0x140/0x240 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:621
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1
 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: 0033:0x7f85b298d99d
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d c1 ab 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffd00be1268 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007ffd00be1370 RCX: 00007f85b298d99d
RDX: 0000000000000004 RSI: 00007ffd00be127c RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000000000a1 R09: 000b615db053d7d4
R10: 00000053a4b3eb0b R11: 0000000000000246 R12: 00007ffd00be1690
R13: 0000000000000004 R14: 00007ffd00be127c R15: 00007ffd00be1310
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3049 Comm: syz.1.613 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: 0018:ffffc900001af480 EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff8881f7127c40 RCX: ffffffff84f43dc2
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8881f7127c40
RBP: ffffc900001af510 R08: dffffc0000000000 R09: ffffed103ee24f89
R10: ffffed103ee24f89 R11: 1ffff1103ee24f88 R12: 1ffff1103ee20001
R13: ffff8881f7138cd4 R14: dffffc0000000000 R15: 1ffff92000035e90
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f035a5722e0 CR3: 0000000006e0f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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_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
 __traceiter_timer_start+0x8c/0xe0 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_rearm_rto+0x312/0x700 net/ipv4/tcp_input.c:3264
 tcp_event_new_data_sent+0x250/0x400 net/ipv4/tcp_output.c:82
 tcp_write_xmit+0x161f/0x5fb0 net/ipv4/tcp_output.c:2717
 __tcp_push_pending_frames+0x9c/0x2f0 net/ipv4/tcp_output.c:2895
 tcp_push_pending_frames include/net/tcp.h:1987 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5605 [inline]
 tcp_rcv_established+0x9ee/0x1a20 net/ipv4/tcp_input.c:6120
 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+0xbe/0xe0 arch/x86/kernel/irq.c:242
 </IRQ>
 <TASK>
 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682
RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:234
Code: 48 0b 00 00 83 fa 02 75 21 48 8b 91 50 0b 00 00 48 8b 32 48 8d 7e 01 8b 89 4c 0b 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <5d> c3 66 90 90 90 90 90 90 90 90 90 90 90 90 b8 e2 33 28 be 55 48
RSP: 0018:ffffc900016c7378 EFLAGS: 00000293
RAX: ffffffff81b1f93b RBX: ffffea0004b99680 RCX: ffff88813a303cc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900016c7378 R08: dffffc0000000000 R09: fffff940009732d1
R10: fffff940009732d1 R11: 1ffffd40009732d0 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffffd40009732d0 R15: dffffc0000000000
 folio_test_swapcache include/linux/page-flags.h:549 [inline]
 free_swap_cache+0x9b/0x160 mm/swap_state.c:285
 free_pages_and_swap_cache+0x60/0xa0 mm/swap_state.c:314
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0x101/0x1e0 mm/mmu_gather.c:261
 zap_pte_range mm/memory.c:1547 [inline]
 zap_pmd_range mm/memory.c:1596 [inline]
 zap_pud_range mm/memory.c:1625 [inline]
 zap_p4d_range mm/memory.c:1646 [inline]
 unmap_page_range+0x20c6/0x2310 mm/memory.c:1667
 unmap_single_vma mm/memory.c:1713 [inline]
 unmap_vmas+0x31c/0x430 mm/memory.c:1753
 exit_mmap+0x268/0xb60 mm/mmap.c:3369
 __mmput+0x93/0x320 kernel/fork.c:1300
 mmput+0x4b/0x150 kernel/fork.c:1323
 exit_mm kernel/exit.c:568 [inline]
 do_exit+0x981/0x2650 kernel/exit.c:873
 do_group_exit+0x210/0x2d0 kernel/exit.c:1028
 get_signal+0x13b5/0x1520 kernel/signal.c:2889
 arch_do_signal_or_restart+0xb0/0x1030 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x7a/0xb0 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f419c98efc9
Code: Unable to access opcode bytes at 0x7f419c98ef9f.
RSP: 002b:00007f419d8d9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: 000000000000000a RBX: 00007f419cbe6090 RCX: 00007f419c98efc9
RDX: 0000000000000010 RSI: 0000200000000040 RDI: 0000000000000011
RBP: 00007f419ca11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f419cbe6128 R14: 00007f419cbe6090 R15: 00007fffee5a5fe8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/27 06:14 android14-6.1 22c0b7236c43 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 BUG: soft lockup in sock_read_iter
2025/09/08 00:14 android14-6.1 499d2a0ffd4f d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 BUG: soft lockup in sock_read_iter
* Struck through repros no longer work on HEAD.