[syzbot] [mptcp?] WARNING in __mptcp_move_skbs_from_subflow

From: syzbot
Date: Mon Jul 15 2024 - 10:28:59 EST

Hello,

syzbot found the following issue on:

HEAD commit: d0d0cd380055 Merge tag '6.10-rc7-smb3-client-fix' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1320b879980000
kernel config: https://syzkaller.appspot.com/x/.config?x=84344463c2ebf8a1
dashboard link: https://syzkaller.appspot.com/bug?extid=d1bff73460e33101f0e7
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-d0d0cd38.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/501bce8ef014/vmlinux-d0d0cd38.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8cca4ce21aed/bzImage-d0d0cd38.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d1bff73460e33101f0e7@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 0 PID: 20604 at net/mptcp/protocol.c:693 __mptcp_move_skbs_from_subflow+0x1677/0x2500 net/mptcp/protocol.c:693
Modules linked in:
CPU: 0 PID: 20604 Comm: syz.3.4228 Not tainted 6.10.0-rc7-syzkaller-00256-gd0d0cd380055 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__mptcp_move_skbs_from_subflow+0x1677/0x2500 net/mptcp/protocol.c:693
Code: 85 04 0e 00 00 c6 43 7f 00 e9 fd ef ff ff e8 b0 e4 d0 f6 90 0f 0b 90 e9 d0 f0 ff ff 4c 8b ac 24 90 00 00 00 e8 9a e4 d0 f6 90 <0f> 0b 90 e9 ae f2 ff ff e8 8c e4 d0 f6 90 0f 0b 90 e9 28 eb ff ff
RSP: 0018:ffffc90000007498 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000000081e5 RCX: ffffffff8abd9c87
RDX: ffff88801ed74880 RSI: ffffffff8abdaa86 RDI: 0000000000000004
RBP: 00000000000055f0 R08: 0000000000000004 R09: 00000000000081e5
R10: 00000000000055f0 R11: 0000000000000007 R12: ffff88805b1ce2e8
R13: ffffc900000075c0 R14: ffff88805b1ce200 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88802c000000(0063) knlGS:00000000f5d5fb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020287000 CR3: 000000001c02c000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
move_skbs_to_msk net/mptcp/protocol.c:809 [inline]
mptcp_data_ready+0x2c5/0x960 net/mptcp/protocol.c:854
subflow_data_ready+0x51d/0x7d0 net/mptcp/subflow.c:1465
tcp_data_ready+0x146/0x5b0 net/ipv4/tcp_input.c:5177
tcp_data_queue+0x1a6f/0x5270 net/ipv4/tcp_input.c:5267
tcp_rcv_established+0x8e9/0x21b0 net/ipv4/tcp_input.c:6210
tcp_v4_do_rcv+0x707/0xab0 net/ipv4/tcp_ipv4.c:1909
tcp_v4_rcv+0x2eb4/0x3c00 net/ipv4/tcp_ipv4.c:2345
ip_protocol_deliver_rcu+0xba/0x4e0 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x316/0x570 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_rcv_finish net/ipv4/ip_input.c:449 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
NF_HOOK include/linux/netfilter.h:308 [inline]
ip_rcv+0x2c5/0x5d0 net/ipv4/ip_input.c:569
__netif_receive_skb_one_core+0x199/0x1e0 net/core/dev.c:5625
__netif_receive_skb+0x1d/0x160 net/core/dev.c:5739
process_backlog+0x133/0x760 net/core/dev.c:6068
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6722
napi_poll net/core/dev.c:6791 [inline]
net_rx_action+0x9b6/0xf10 net/core/dev.c:6907
handle_softirqs+0x216/0x8f0 kernel/softirq.c:554
do_softirq kernel/softirq.c:455 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:442
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:382
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:851 [inline]
__dev_queue_xmit+0x872/0x4130 net/core/dev.c:4420
dev_queue_xmit include/linux/netdevice.h:3095 [inline]
neigh_hh_output include/net/neighbour.h:526 [inline]
neigh_output include/net/neighbour.h:540 [inline]
ip_finish_output2+0x16bf/0x2590 net/ipv4/ip_output.c:235
__ip_finish_output net/ipv4/ip_output.c:313 [inline]
__ip_finish_output+0x49e/0x950 net/ipv4/ip_output.c:295
ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:323
NF_HOOK_COND include/linux/netfilter.h:303 [inline]
ip_output+0x13b/0x2a0 net/ipv4/ip_output.c:433
dst_output include/net/dst.h:450 [inline]
ip_local_out+0x33e/0x4a0 net/ipv4/ip_output.c:129
__ip_queue_xmit+0x747/0x1940 net/ipv4/ip_output.c:535
__tcp_transmit_skb+0x29c1/0x3da0 net/ipv4/tcp_output.c:1466
tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
tcp_mtu_probe net/ipv4/tcp_output.c:2546 [inline]
tcp_write_xmit+0x83f4/0x87e0 net/ipv4/tcp_output.c:2751
__tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3014
tcp_push_pending_frames include/net/tcp.h:2102 [inline]
tcp_data_snd_check net/ipv4/tcp_input.c:5693 [inline]
tcp_rcv_established+0x972/0x21b0 net/ipv4/tcp_input.c:6212
tcp_v4_do_rcv+0x707/0xab0 net/ipv4/tcp_ipv4.c:1909
sk_backlog_rcv include/net/sock.h:1106 [inline]
__release_sock+0x31b/0x400 net/core/sock.c:2983
release_sock+0x5a/0x220 net/core/sock.c:3549
__mptcp_push_pending+0x400/0x560 net/mptcp/protocol.c:1623
mptcp_sendmsg+0xce5/0x1f20 net/mptcp/protocol.c:1901
inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:853
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x42c/0x4e0 net/socket.c:2192
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__ia32_sys_sendto+0xdd/0x1b0 net/socket.c:2200
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7447579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5d5f57c EFLAGS: 00000292 ORIG_RAX: 0000000000000171
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000200000c0
RDX: 00000000fffffe44 RSI: 0000000004000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi


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