Description
In the Linux kernel, the following vulnerability has been resolved: gpib: fix double decrement of descriptor_busy in command_ioctl() commit d1857f8296dc ("gpib: fix use-after-free in IO ioctl handlers") introduced a descriptor_busy reference counter to pin struct gpib_descriptor across IO ioctl operations. In command_ioctl(), the error path inside the loop decrements descriptor_busy and breaks, but execution then falls through to the unconditional decrement after the loop, underflowing the counter to -1. This re-enables the use-after-free that the original fix was meant to prevent: a concurrent close_dev_ioctl() sees descriptor_busy == 0 on an actively-used descriptor and frees it. Remove the early decrement from the error path. The post-loop decrement already handles all exit paths, matching the correct pattern used in read_ioctl() and write_ioctl().
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
cae26eff1b56d78bed7873cf3e60a2b1bdd4da6c to < fdee9f207a48ce204ec6cfceaa1459d2473600a5affectedd1857f8296dceb75d00ab857fc3c61bc00c7f5c6 to < 8b5f1d295dda8677e4545ce340053fcfa8b634c7affectedd1857f8296dceb75d00ab857fc3c61bc00c7f5c6 to < c4faab452b3c1ada003d49c477609dd80523b9bfaffected28c75dd143ead62e0dfac564c79d251e21d5d74baffected6.18.22 to < 6.18.40affected6.19.12 to < 6.20affected
Linux Linux
Default version status: affected
7.0affected0 to < 7.0unaffected6.18.40 to ≤ 6.18.*unaffected7.1.5 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected