If offset (range[0]) is greater than device size (blksize), the variable 'end'
will be greater than blksize, and range[1] (length) will be recalculated.
The underflow happens when subtracting range[0] (offset) from blksize, thus
range[1] will be the result of an underflow. The bug leads to unwanted behavior
from the program, where range[1] is likely to be a high number and then will
discard a considerable amount of blocks from the device. The fix consists of
exitting the program with an error message when the condition stated above is
true. Spotted while auditing the code.
Signed-off-by: Raphael S. Carvalho <raphaelsc@cloudius-systems.com>
Calling function "open(char const *, int, ...)" that uses "path" after
a check function. This can cause a time-of-check, time-of-use race
condition.
.. well, in blkdiscard context it's mostly cosmetic change.
Signed-off-by: Karel Zak <kzak@redhat.com>
blkdiscard is used to discard device sectors. This is useful for
solid-state drivers (SSDs) and thinly-provisioned storage. Unlike
fstrim this command is used directly on the block device.
blkkdiscard uses BLKDISCARD ioctl or BLKSECDISCARD ioctl for the secure
discard.
All data in the discarded region on the device will be lost!
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Karel Zak
Federico Simoncelli
Raphael S. Carvalho
Theodore Ts'o
Benno Schulenberg
Lukas Czerner