Описание
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().
A flaw was found in the gpib component of the Linux kernel. A double decrement of a descriptor counter within the command_ioctl() function can lead to a counter underflow. This re-enables a use-after-free vulnerability, where a concurrently active descriptor can be prematurely freed. This could result in system instability, a denial of service, or potentially allow for arbitrary code execution.
Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
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().
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().
In the Linux kernel, the following vulnerability has been resolved: g ...
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().
EPSS
5.5 Medium
CVSS3