KCSAN: data-race in dev_uevent / really_probe (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c84e1efa Merge tag 'asm-generic-fixes-5.10-2' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122c418b500000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9b19d1bde60f8d
dashboard link: https://syzkaller.appspot.com/bug?extid=d8ff3efb82af55a2745d
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org raf...@kernel.org]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d8ff3e...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in dev_uevent / really_probe

write to 0xffff88812cef8908 of 8 bytes by task 8916 on cpu 1:
really_probe+0xe2/0xb70 drivers/base/dd.c:528
driver_probe_device+0xcc/0x120 drivers/base/dd.c:738
__device_attach_driver+0x255/0x290 drivers/base/dd.c:844
bus_for_each_drv+0xd8/0x140 drivers/base/bus.c:431
__device_attach+0x1a0/0x290 drivers/base/dd.c:912
device_initial_probe+0x16/0x20 drivers/base/dd.c:959
bus_probe_device+0x7a/0x140 drivers/base/bus.c:491
device_add+0x109c/0x1210 drivers/base/core.c:2936
usb_new_device+0x719/0xc80 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5222 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5362 [inline]
port_event drivers/usb/core/hub.c:5508 [inline]
hub_event+0x1d25/0x2b60 drivers/usb/core/hub.c:5590
process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
worker_thread+0x635/0xb90 kernel/workqueue.c:2418
kthread+0x1fd/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff88812cef8908 of 8 bytes by task 4878 on cpu 0:
dev_uevent+0x213/0x350 drivers/base/core.c:1897
uevent_show+0x10e/0x1f0 drivers/base/core.c:1969
dev_attr_show+0x35/0x90 drivers/base/core.c:1671
sysfs_kf_seq_show+0x152/0x270 fs/sysfs/file.c:61
kernfs_seq_show+0x74/0x80 fs/kernfs/file.c:167
seq_read_iter+0x2ef/0x8e0 fs/seq_file.c:228
seq_read+0x221/0x260 fs/seq_file.c:159
kernfs_fop_read+0xce/0x2f0 fs/kernfs/file.c:251
vfs_read+0x154/0x5c0 fs/read_write.c:494
ksys_read+0xce/0x180 fs/read_write.c:634
__do_sys_read fs/read_write.c:644 [inline]
__se_sys_read fs/read_write.c:642 [inline]
__x64_sys_read+0x3e/0x50 fs/read_write.c:642
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4878 Comm: systemd-journal Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

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