[syzbot] [usb?] KASAN: vmalloc-out-of-bounds Read in kcov_remote_start

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d104e3d17f7b Merge tag 'cxl-for-6.18' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1146b942580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ccc18dddafa95b97
dashboard link: https://syzkaller.appspot.com/bug?extid=8a173e13208949931dc7
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/335d7c35cbbe/disk-d104e3d1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/72dbd901415b/vmlinux-d104e3d1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3ff1353d0870/bzImage-d104e3d1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8a173e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
Read of size 8 at addr ffffc9000d912008 by task kworker/1:5/5918

CPU: 1 UID: 0 PID: 5918 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
__list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
__list_del_entry_valid include/linux/list.h:132 [inline]
__list_del_entry include/linux/list.h:223 [inline]
list_del include/linux/list.h:237 [inline]
kcov_remote_area_get kernel/kcov.c:143 [inline]
kcov_remote_start+0x2b0/0x6f0 kernel/kcov.c:906
kcov_remote_start_usb include/linux/kcov.h:55 [inline]
hub_event+0x158/0x4a20 drivers/usb/core/hub.c:5888
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>

The buggy address belongs to a vmalloc virtual mapping
Memory state around the buggy address:
ffffc9000d911f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc9000d911f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc9000d912000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc9000d912080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc9000d912100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================


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