[v6.1] general protection fault in vhci_hcd_probe

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1012a679580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=a72fc49911749afccb9a
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/156843a60452/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/719d532a0151/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/12160bc2f9ec/bzImage-e4f7d8be.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a72fc4...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 4983 Comm: syz.1.154 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:vhci_hcd_probe+0x43/0x370 drivers/usb/usbip/vhci_hcd.c:1365
Code: 83 1b e8 fa 49 8d 9e 80 00 00 00 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 27 48 39 fb 48 8b 1b 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 0f 48 39 fb 4c 8b 2b 48 c7 c0 20 82
RSP: 0018:ffffc90005d57a78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000c4d1000 RSI: 0000000000000d01 RDI: 0000000000000d02
RBP: dffffc0000000000 R08: ffff888146bf5743 R09: 1ffff11028d7eae8
R10: dffffc0000000000 R11: ffffed1028d7eae9 R12: ffff8880206b13d0
R13: ffffffff8d8119a0 R14: ffff8880206b1000 R15: 1ffffffff1b02334
FS: 00007fe35559b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ff23ffc CR3: 000000007b5ac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
platform_probe+0x137/0x1c0 drivers/base/platform.c:1400
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x24a/0xb40 drivers/base/dd.c:638
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
device_driver_attach+0xd9/0x1c0 drivers/base/dd.c:1131
bind_store+0x33b/0x380 drivers/base/bus.c:216
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe35479e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe35559b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe354a25fa0 RCX: 00007fe35479e0d9
RDX: 0000000000000006 RSI: 00002000000001c0 RDI: 0000000000000004
RBP: 00007fe354835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe354a26038 R14: 00007fe354a25fa0 R15: 00007ffefc5a5988
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:vhci_hcd_probe+0x43/0x370 drivers/usb/usbip/vhci_hcd.c:1365
Code: 83 1b e8 fa 49 8d 9e 80 00 00 00 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 27 48 39 fb 48 8b 1b 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 0f 48 39 fb 4c 8b 2b 48 c7 c0 20 82
RSP: 0018:ffffc90005d57a78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000c4d1000 RSI: 0000000000000d01 RDI: 0000000000000d02
RBP: dffffc0000000000 R08: ffff888146bf5743 R09: 1ffff11028d7eae8
R10: dffffc0000000000 R11: ffffed1028d7eae9 R12: ffff8880206b13d0
R13: ffffffff8d8119a0 R14: ffff8880206b1000 R15: 1ffffffff1b02334
FS: 00007fe35559b6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f06cadf3000 CR3: 000000007b5ac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 83 1b e8 sbbl $0xffffffe8,(%rbx)
3: fa cli
4: 49 8d 9e 80 00 00 00 lea 0x80(%r14),%rbx
b: 48 89 d8 mov %rbx,%rax
e: 48 c1 e8 03 shr $0x3,%rax
12: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1)
16: 74 08 je 0x20
18: 48 89 df mov %rbx,%rdi
1b: e8 27 48 39 fb call 0xfb394847
20: 48 8b 1b mov (%rbx),%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 48 89 df mov %rbx,%rdi
33: e8 0f 48 39 fb call 0xfb394847
38: 4c 8b 2b mov (%rbx),%r13
3b: 48 rex.W
3c: c7 .byte 0xc7
3d: c0 20 82 shlb $0x82,(%rax)


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