In the Linux kernel, the following vulnerability has been resolved:
USB: ldusb: fix use-after-free on disconnect race
mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (unlike spinlocks and refcounts). [1][2]
Use a kref to release the driver data to avoid use-after-free in mutex_unlock() when release() races with disconnect().
[1] a51749ab34d9 (locking/mutex: Document that mutex_unlock() is non-atomic) [2] 2b9d9e0a9ba0 (locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after its unlocked)
References
- https://git.kernel.org/stable/c/02ca08fff74cf9b0a3c4d2cacde1c6edeeb95bb4
- https://git.kernel.org/stable/c/19bdfc7b3c179331eafa423d87e1336f43bbfeb8
- https://git.kernel.org/stable/c/2107a4fc8ff1cf1d52f416c1e5cc8e97413a5915
- https://git.kernel.org/stable/c/a3e794136ab5e3ad1e7019175a4b837aec86db4b
- https://git.kernel.org/stable/c/af59829e67e11ba2511a9f8e4b9111afc7d1f550
- https://git.kernel.org/stable/c/d8f69404e1d671326f86d378b9f5bfbd56490e9d
- https://git.kernel.org/stable/c/e5a9bdce4bfd3e2226b5f3df5fb8385d6935ee69
- https://git.kernel.org/stable/c/fc55923a972e715f9a27187b47d4920709e23d85