From: Anirudh Rayabharam Date: Sun, 16 May 2021 19:27:14 +0000 (+0530) Subject: video: hgafb: correctly handle card detect failure during probe X-Git-Tag: v4.4.270~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e7a48689d1e5ac2071baae98df356972d01dbf5e;p=thirdparty%2Fkernel%2Fstable.git video: hgafb: correctly handle card detect failure during probe commit 02625c965239b71869326dd0461615f27307ecb3 upstream. 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/ Fixes: dc13cac4862c ("video: hgafb: fix potential NULL pointer dereference") Cc: stable Reported-by: kernel test robot Reviewed-by: Igor Matheus Andrade Torrente Signed-off-by: Anirudh Rayabharam Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/20210516192714.25823-1-mail@anirudhrb.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/video/fbdev/hgafb.c b/drivers/video/fbdev/hgafb.c index 9d15abd7893db..46ac8bbb376d1 100644 --- a/drivers/video/fbdev/hgafb.c +++ b/drivers/video/fbdev/hgafb.c @@ -558,7 +558,7 @@ static int hgafb_probe(struct platform_device *pdev) int ret; ret = hga_card_detect(); - if (!ret) + if (ret) return ret; printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n",