mkrasimage: fix segmentation fault

Code was attempting to determine the size of the file
before it was actually known and allocating insufficient
memory space.  Images above a certain size caused a
segmentation fault.  Moving the calloc() ensured ensured
that large images didn't result in a buffer overflow on
memcpy().

Signed-off-by: Michael T Farnworth <michael@turf.org>
[fixed name in From to match one in SoB]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
This commit is contained in:
Michael T Farnworth 2020-02-22 14:20:49 +00:00 committed by Petr Štetiar
parent c60be19693
commit b468353a37
1 changed files with 10 additions and 9 deletions

View File

@ -317,6 +317,16 @@ int build_image()
map_file(&kernel);
map_file(&rootfs);
/* As ZyXEL Web-GUI only accept images with a rootfs equal or larger than the first firmware shipped
* for the device, we need to pad rootfs partition to this size. To perform further calculations, we
* decide the size of this part here. In case the rootfs we want to integrate in our image is larger,
* take it's size, otherwise the supplied size.
*
* Be careful! We rely on assertion of correct size to be performed beforehand. It is unknown if images
* with a to large rootfs are accepted or not.
*/
rootfs_out.size = rootfs_size < rootfs.size ? rootfs.size : rootfs_size;
/*
* Allocate memory and copy input rootfs for temporary output rootfs.
* This is important as we have to generate the rootfs checksum over the
@ -451,14 +461,5 @@ int main(int argc, char *argv[])
if (ret)
usage(EXIT_FAILURE);
/* As ZyXEL Web-GUI only accept images with a rootfs equal or larger than the first firmware shipped
* for the device, we need to pad rootfs partition to this size. To perform further calculations, we
* decide the size of this part here. In case the rootfs we want to integrate in our image is larger,
* take it's size, otherwise the supplied size.
*
* Be careful! We rely on assertion of correct size to be performed beforehand. It is unknown if images
* with a to large rootfs are accepted or not.
*/
rootfs_out.size = rootfs_size < rootfs.size ? rootfs.size : rootfs_size;
return build_image();
}