usb: gadget: f_tcm: fix deadlock in usbg_make_tpg()

usbg_make_tpg() held dep_lock while calling
configfs_depend_item_unlocked(), which acquires the configfs root
inode lock when operating across subsystems. This creates a circular
lock dependency with configfs_rmdir():

  dep_lock -> configfs root inode lock -> su_mutex -> dep_lock

In usbg_make_tpg(), dep_lock only serialized the read of opts->ready,
which is a monotonic flag that transitions from false to true exactly
once (in tcm_set_name()) and never reverts. Remove dep_lock from
usbg_make_tpg() entirely and use READ_ONCE/WRITE_ONCE to access
opts->ready locklessly instead.

Reported-by: syzbot+c9f9d646b08f3b6032fe@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c9f9d646b08f3b6032fe
Fixes: 4bb8548df632 ("usb: gadget: f_tcm: add configfs support")
Cc: stable@vger.kernel.org
Signed-off-by: Yun Zhou <yun.zhou@windriver.com>
Link: https://patch.msgid.link/20260731081151.285599-1-yun.zhou@windriver.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions