[moderation] [usb?] general protection fault in vhci_send_cmd_submit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9d9c1cfec01c Merge tag 'mm-nonmm-stable-2025-12-11-11-47' ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113a89c2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8bfa57a8c0ab3aa8
dashboard link: https://syzkaller.appspot.com/bug?extid=89bfa88d3aea28f58944
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386
CC: [gre...@linuxfoundation.org i...@zenithal.me linux-...@vger.kernel.org linu...@vger.kernel.org sh...@kernel.org valentin...@gmail.com]

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-9d9c1cfe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a72f549ab488/vmlinux-9d9c1cfe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9d102d45647c/bzImage-9d9c1cfe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+89bfa8...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 2 UID: 0 PID: 12727 Comm: vhci_tx Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:setup_cmd_submit_pdu drivers/usb/usbip/vhci_tx.c:16 [inline]
RIP: 0010:vhci_send_cmd_submit+0x42b/0x1190 drivers/usb/usbip/vhci_tx.c:95
Code: e8 ba 0f 39 fa 48 8d 7b 08 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 fb 0a 00 00 4c 8b 63 08 49 8d 7c 24 18 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 40 0b 00 00 48 c7 c0 80 fa f1 9a 4d 8b 74 24 18
RSP: 0018:ffffc90028427af8 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff8880207aa500 RCX: ffffffff878535fc
RDX: ffff888024a3a4c0 RSI: ffffffff87853636 RDI: 0000000000000018
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000002b91 R12: 0000000000000000
R13: ffff88806cc03200 R14: 0000000000000000 R15: ffff8880207aa584
FS: 0000000000000000(0000) GS:ffff888097901000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f50e3619 CR3: 0000000070b1a000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
vhci_tx_loop+0xff/0x460 drivers/usb/usbip/vhci_tx.c:241
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:setup_cmd_submit_pdu drivers/usb/usbip/vhci_tx.c:16 [inline]
RIP: 0010:vhci_send_cmd_submit+0x42b/0x1190 drivers/usb/usbip/vhci_tx.c:95
Code: e8 ba 0f 39 fa 48 8d 7b 08 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 fb 0a 00 00 4c 8b 63 08 49 8d 7c 24 18 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 40 0b 00 00 48 c7 c0 80 fa f1 9a 4d 8b 74 24 18
RSP: 0018:ffffc90028427af8 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff8880207aa500 RCX: ffffffff878535fc
RDX: ffff888024a3a4c0 RSI: ffffffff87853636 RDI: 0000000000000018
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000002b91 R12: 0000000000000000
R13: ffff88806cc03200 R14: 0000000000000000 R15: ffff8880207aa584
FS: 0000000000000000(0000) GS:ffff888097a01000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005580742b8000 CR3: 0000000027a17000 CR4: 0000000000352ef0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: e8 ba 0f 39 fa call 0xfa390fbf
5: 48 8d 7b 08 lea 0x8(%rbx),%rdi
9: 48 89 f8 mov %rdi,%rax
c: 48 c1 e8 03 shr $0x3,%rax
10: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1)
14: 0f 85 fb 0a 00 00 jne 0xb15
1a: 4c 8b 63 08 mov 0x8(%rbx),%r12
1e: 49 8d 7c 24 18 lea 0x18(%r12),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction
2e: 0f 85 40 0b 00 00 jne 0xb74
34: 48 c7 c0 80 fa f1 9a mov $0xffffffff9af1fa80,%rax
3b: 4d 8b 74 24 18 mov 0x18(%r12),%r14


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