In the Linux kernel, the following vulnerability has been resolved:
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.
References 8
https://git.kernel.org/stable/c/3639438a4c83ffc2e564c8c010b92137c5d11cfa
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6bcd9ee6ad6989d1d85a7459687e45b7ad7568d9
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/78a14ea2284825055ab6c2a1f3489510f560f3a2
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9dbf74f4022f80f7669d2b3c22c5deb46c1b5674
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/abad5daa41cf5d0a0a9cba0397d3a0e7f11e0277
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/d90b0f90e30cd59b36005a4016b15cf02bcd7fb2
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/eef3e62f90d86c1c5651742f84ecc9db1814a893
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f81a2da137b029a282b9bc64d2f267d242948659
416baaa9-dc9f-4396-8d5f-8c081fb06d67