[moderation] [usb?] KCSAN: data-race in mon_reader_add / usb_hcd_submit_urb (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c6859eed755d Merge tag 's390-7.2-5' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1373dcb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b3039e8461eef5
dashboard link: https://syzkaller.appspot.com/bug?extid=3fa6a61c46391803c918
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org linu...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/54889173a21b/disk-c6859eed.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b96168b14a14/vmlinux-c6859eed.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d069c1e4b7c7/bzImage-c6859eed.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3fa6a6...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in mon_reader_add / usb_hcd_submit_urb

write to 0xffff888100b84080 of 4 bytes by task 22254 on cpu 0:
mon_reader_add+0xc0/0x1d0 drivers/usb/mon/mon_main.c:47
mon_bin_open+0x321/0x3a0 drivers/usb/mon/mon_bin.c:722
chrdev_open+0x2eb/0x3a0 fs/char_dev.c:411
do_dentry_open+0x49f/0xa60 fs/open.c:947
vfs_open+0x37/0x1e0 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x1b39/0x2000 fs/namei.c:4863
do_file_open+0x16c/0x290 fs/namei.c:4892
do_sys_openat2+0xa0/0x130 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0xf2/0x120 fs/open.c:1385
x64_sys_call+0x1e39/0x3020 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100b84080 of 4 bytes by task 26699 on cpu 1:
usbmon_urb_submit include/linux/usb/hcd.h:723 [inline]
usb_hcd_submit_urb+0x64/0x11f0 drivers/usb/core/hcd.c:1527
usb_submit_urb+0xaa3/0xbb0 drivers/usb/core/urb.c:586
usb_start_wait_urb+0x91/0x220 drivers/usb/core/message.c:62
usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
usb_control_msg+0x182/0x240 drivers/usb/core/message.c:167
get_port_status drivers/usb/core/hub.c:607 [inline]
hub_ext_port_status+0xc2/0x470 drivers/usb/core/hub.c:624
usb_hub_port_status drivers/usb/core/hub.c:674 [inline]
port_event drivers/usb/core/hub.c:5761 [inline]
hub_event+0x47e/0x2aa0 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405
worker_thread+0x569/0x750 kernel/workqueue.c:3486
kthread+0x221/0x270 kernel/kthread.c:436
ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 26699 Comm: kworker/1:17 Tainted: G W syzkaller #0 PREEMPT(lazy)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: usb_hub_wq hub_event
==================================================================


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