syzbot

 sign-in | mailing list | source | docs
🐞 Open [1471]
≡ Subsystems
🐞 Fixed [6810]
🐞 Invalid [17611]
⬇ Missing Backports [225]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

WARNING in subflow_data_ready (3)

Status: closed as invalid on 2025/06/27 12:28
Subsystems: mptcp
[Documentation on labels]
First crash: 208d, last: 208d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in subflow_data_ready mptcp -1 42 707d 791d 25/29 fixed on 2024/01/20 21:18
linux-6.1 WARNING in subflow_data_ready origin:lts-only -1 C unreliable 6 569d 713d 0/3 upstream: reported C repro on 2024/01/11 08:07
upstream WARNING in subflow_data_ready (2) mptcp -1 C done 9 682d 700d 0/29 auto-obsoleted due to no activity on 2024/05/21 09:30
upstream WARNING in subflow_data_ready (4) mptcp -1 C 451 9m 126d 1/29 upstream: reported C repro on 2025/08/20 12:41
linux-6.6 WARNING in subflow_data_ready origin:upstream -1 C 13 11d 14d 0/2 upstream: reported C repro on 2025/12/10 13:17

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7870 at net/mptcp/subflow.c:1505 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1505
Modules linked in:
CPU: 1 UID: 0 PID: 7870 Comm: syz.3.451 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1505
Code: 89 ee e8 98 f2 56 f6 40 84 ed 75 21 e8 ae f7 56 f6 44 89 fe bf 07 00 00 00 e8 e1 f2 56 f6 41 83 ff 07 74 09 e8 96 f7 56 f6 90 <0f> 0b 90 e8 8d f7 56 f6 48 89 df e8 85 b0 ff ff 31 ff 89 c5 89 c6
RSP: 0018:ffffc90000590578 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888070da1980 RCX: ffffffff8b645eaf
RDX: ffff88802355c880 RSI: ffffffff8b645eba RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
R10: 0000000000000004 R11: 0000000000000001 R12: ffff888061fd1700
R13: 1ffff920000b20af R14: ffff888021105400 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff88809787b000(0000) knlGS:0000000000000000
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002f5ceffc CR3: 000000006e807000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 tcp_data_queue+0x13a4/0x4f50 net/ipv4/tcp_input.c:5302
 tcp_rcv_state_process+0xfe8/0x4ed0 net/ipv4/tcp_input.c:7014
 tcp_v4_do_rcv+0x1ad/0xa90 net/ipv4/tcp_ipv4.c:1948
 tcp_v4_rcv+0x3609/0x4650 net/ipv4/tcp_ipv4.c:2363
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:317 [inline]
 NF_HOOK include/linux/netfilter.h:311 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:469 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 NF_HOOK include/linux/netfilter.h:311 [inline]
 ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5977
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6090
 process_backlog+0x442/0x15e0 net/core/dev.c:6442
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 ca bc 1c f6 48 89 df e8 b2 10 1d f6 e8 8d eb 47 f6 fb bf 01 00 00 00 <e8> 52 38 0d f6 65 8b 05 db 12 2f 08 85 c0 74 06 5b e9 41 4d 00 00
RSP: 0018:ffffc900079273b0 EFLAGS: 00000202
RAX: 0000000000007857 RBX: ffff88804d715f18 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8dc00788 RDI: 0000000000000001
RBP: ffff88804d715f10 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90878157 R11: 0000000000000001 R12: ffff88804d715f18
R13: ffff88804d715f10 R14: ffffc900079276e0 R15: 000000000000001d
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 filemap_remove_folio+0x106/0x250 mm/filemap.c:254
 truncate_inode_folio+0x49/0x70 mm/truncate.c:176
 shmem_undo_range+0x376/0x1150 mm/shmem.c:1121
 shmem_truncate_range mm/shmem.c:1237 [inline]
 shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1365
 evict+0x3e3/0x920 fs/inode.c:810
 iput_final fs/inode.c:1898 [inline]
 iput fs/inode.c:1924 [inline]
 iput+0x521/0x880 fs/inode.c:1910
 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466
 __dentry_kill+0x1d0/0x600 fs/dcache.c:669
 dput.part.0+0x4b1/0x9b0 fs/dcache.c:911
 dput+0x1f/0x30 fs/dcache.c:901
 __fput+0x51c/0xb70 fs/file_table.c:473
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xae2/0x2c70 kernel/exit.c:959
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1108
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 __do_fast_syscall_32+0x2ac/0x3a0 arch/x86/entry/syscall_32.c:309
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f41579
Code: Unable to access opcode bytes at 0xf7f4154f.
RSP: 002b:00000000f4c0160c EFLAGS: 00000296 ORIG_RAX: 00000000000000f0
RAX: fffffffffffffe00 RBX: 00000000f7405138 RCX: 0000000000000080
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f740513c
RBP: 0000000000000081 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	f3 0f 1e fa          	endbr64
   5:	53                   	push   %rbx
   6:	48 8b 74 24 08       	mov    0x8(%rsp),%rsi
   b:	48 89 fb             	mov    %rdi,%rbx
   e:	48 83 c7 18          	add    $0x18,%rdi
  12:	e8 ca bc 1c f6       	call   0xf61cbce1
  17:	48 89 df             	mov    %rbx,%rdi
  1a:	e8 b2 10 1d f6       	call   0xf61d10d1
  1f:	e8 8d eb 47 f6       	call   0xf647ebb1
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 52 38 0d f6       	call   0xf60d3881 <-- trapping instruction
  2f:	65 8b 05 db 12 2f 08 	mov    %gs:0x82f12db(%rip),%eax        # 0x82f1311
  36:	85 c0                	test   %eax,%eax
  38:	74 06                	je     0x40
  3a:	5b                   	pop    %rbx
  3b:	e9 41 4d 00 00       	jmp    0x4d81

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/31 01:52 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in subflow_data_ready
* Struck through repros no longer work on HEAD.