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authorZhang Shurong <zhang_shurong@foxmail.com>2023-06-24 19:16:49 +0300
committerHelge Deller <deller@gmx.de>2023-06-24 22:55:11 +0300
commitc2d22806aecb24e2de55c30a06e5d6eb297d161d (patch)
tree6430650d618a7f86bf428e942cb7bfbf3f1b1d3c /drivers/video
parent29c171de52bcef23a7593a890cbcb6761be0123c (diff)
downloadlinux-c2d22806aecb24e2de55c30a06e5d6eb297d161d.tar.xz
fbdev: fix potential OOB read in fast_imageblit()
There is a potential OOB read at fast_imageblit, for "colortab[(*src >> 4)]" can become a negative value due to "const char *s = image->data, *src". This change makes sure the index for colortab always positive or zero. Similar commit: https://patchwork.kernel.org/patch/11746067 Potential bug report: https://groups.google.com/g/syzkaller-bugs/c/9ubBXKeKXf4/m/k-QXy4UgAAAJ Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fbdev/core/sysimgblt.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/video/fbdev/core/sysimgblt.c b/drivers/video/fbdev/core/sysimgblt.c
index 335e92b813fc..665ef7a0a249 100644
--- a/drivers/video/fbdev/core/sysimgblt.c
+++ b/drivers/video/fbdev/core/sysimgblt.c
@@ -189,7 +189,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p,
u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel;
u32 ppw = 32/bpp, spitch = (image->width + 7)/8;
u32 bit_mask, eorx, shift;
- const char *s = image->data, *src;
+ const u8 *s = image->data, *src;
u32 *dst;
const u32 *tab;
size_t tablen;