Re: [PATCH] video: hgafb: correctly handle card detect failure during probe

On Thu, May 20, 2021 at 07:10:39PM +0530, Anirudh Rayabharam wrote:

On Mon, May 17, 2021 at 12:57:14AM +0530, Anirudh Rayabharam wrote:

quoted

The return value of hga_card_detect() is not properly handled causing
the probe to succeed even though hga_card_detect() failed. Since probe
succeeds, hgafb_open() can be called which will end up operating on an
unmapped hga_vram. This results in an out-of-bounds access as reported
by kernel test robot [1].

To fix this, correctly detect failure of hga_card_detect() by checking
for a non-zero error code.

[1]: https://lore.kernel.org/lkml/20210516150019.GB25903@xsang-OptiPlex-9020/ (local)

Reported-by: kernel test robot <redacted>
Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference")

Greg, this is one of the UMN fixes we did. So, do you want to take this
patch into your tree?

Yes, will queue it up in a few days after Linus takes the current pull
request I sent him for this.

thanks,

greg k-h