[moderation] [net?] [usb?] general protection fault in defer_bh

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9b2ffa6148b1 Merge tag 'mtd/fixes-for-6.13-rc5' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=116362f8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=aa8dc22aa6de51f5
dashboard link: https://syzkaller.appspot.com/bug?extid=fb3104d073112b89989d
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
CC: [andrew...@lunn.ch da...@davemloft.net edum...@google.com ku...@kernel.org linux-...@vger.kernel.org linu...@vger.kernel.org net...@vger.kernel.org one...@suse.com pab...@redhat.com]

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-9b2ffa61.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cd632c833a3f/vmlinux-9b2ffa61.xz
kernel image: https://storage.googleapis.com/syzbot-assets/25241b47c08c/bzImage-9b2ffa61.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fb3104...@syzkaller.appspotmail.com

cdc_mbim 8-1:1.0: wdm_int_callback - usb_submit_urb failed with result -1
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 UID: 0 PID: 29 Comm: ksoftirqd/1 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #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:__skb_unlink include/linux/skbuff.h:2428 [inline]
RIP: 0010:defer_bh+0xf5/0x360 drivers/net/usb/usbnet.c:443
Code: 00 00 48 8d 78 08 4c 8b 6b 08 48 b9 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 fe 48 c7 03 00 00 00 00 48 c1 ee 03 <80> 3c 0e 00 0f 85 de 01 00 00 4c 89 ee 4c 89 68 08 48 b9 00 00 00
RSP: 0018:ffffc90000687978 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff888023f6fb80 RCX: dffffc0000000000
RDX: 1ffff110047edf70 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffff888050d04d80 R08: 0000000000000001 R09: fffff520000d0f1d
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888023f6fb88
R13: 0000000000000000 R14: ffff888050d04fa8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3f6629ff8 CR3: 00000000321be000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
rx_complete+0x63a/0xbe0 drivers/net/usb/usbnet.c:665
__usb_hcd_giveback_urb+0x389/0x6e0 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x396/0x450 drivers/usb/core/hcd.c:1734
dummy_timer+0x17f7/0x3960 drivers/usb/gadget/udc/dummy_hcd.c:1993
__run_hrtimer kernel/time/hrtimer.c:1739 [inline]
__hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1803
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1820
handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
run_ksoftirqd kernel/softirq.c:950 [inline]
run_ksoftirqd+0x3a/0x60 kernel/softirq.c:942
smpboot_thread_fn+0x661/0xa30 kernel/smpboot.c:164
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__skb_unlink include/linux/skbuff.h:2428 [inline]
RIP: 0010:defer_bh+0xf5/0x360 drivers/net/usb/usbnet.c:443
Code: 00 00 48 8d 78 08 4c 8b 6b 08 48 b9 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 fe 48 c7 03 00 00 00 00 48 c1 ee 03 <80> 3c 0e 00 0f 85 de 01 00 00 4c 89 ee 4c 89 68 08 48 b9 00 00 00
RSP: 0018:ffffc90000687978 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff888023f6fb80 RCX: dffffc0000000000
RDX: 1ffff110047edf70 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffff888050d04d80 R08: 0000000000000001 R09: fffff520000d0f1d
R10: 0000000000000003 R11: 0000000000000000 R12: ffff888023f6fb88
R13: 0000000000000000 R14: ffff888050d04fa8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe3f6629ff8 CR3: 00000000321be000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 48 8d 78 08 lea 0x8(%rax),%rdi
6: 4c 8b 6b 08 mov 0x8(%rbx),%r13
a: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
11: fc ff df
14: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx)
1b: 00
1c: 48 89 fe mov %rdi,%rsi
1f: 48 c7 03 00 00 00 00 movq $0x0,(%rbx)
26: 48 c1 ee 03 shr $0x3,%rsi
* 2a: 80 3c 0e 00 cmpb $0x0,(%rsi,%rcx,1) <-- trapping instruction
2e: 0f 85 de 01 00 00 jne 0x212
34: 4c 89 ee mov %r13,%rsi
37: 4c 89 68 08 mov %r13,0x8(%rax)
3b: 48 rex.W
3c: b9 .byte 0xb9
3d: 00 00 add %al,(%rax)


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.