USB: iowarrior: fix use-after-free on disconnect race

Overview

In the Linux kernel, the following vulnerability has been resolved:

USB: iowarrior: 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 it's unlocked")

Affected

• Linux >= 946b960d13c15f050a3b848987aaca79f6a459b7 < 4e7d3c98fed73d3be84d3e146d8d9be0309e725b
• Linux >= 946b960d13c15f050a3b848987aaca79f6a459b7 < 3c0a7b29ebb391d5f50b115e86f842b709195b08
• Linux >= 946b960d13c15f050a3b848987aaca79f6a459b7 < 30ec3025b771511625375fb3fb959aea3b45fb0d
• Linux >= 946b960d13c15f050a3b848987aaca79f6a459b7 < 71590982700fdeb39a37a500c877228b0140978e
• Linux >= 946b960d13c15f050a3b848987aaca79f6a459b7 < c602254ba4c10f60a73cd99d147874f86a3f485c
• Linux 2.6.21

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.