This is a note to let you know that I've just added the patch titled

video: fbdev: fix OOB read in vga_8planes_imageblit()

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From bd018a6a75cebb511bb55a0e7690024be975fe93 Mon Sep 17 00:00:00 2001

From: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp Date: Mon, 31 Aug 2020 19:37:00 +0900 Subject: video: fbdev: fix OOB read in vga_8planes_imageblit()

syzbot is reporting OOB read at vga_8planes_imageblit() [1], for "cdat[y] >> 4" can become a negative value due to "const char *cdat".

[1] https://syzkaller.appspot.com/bug?id=0d7a0da1557dcd1989e00cb3692b26d4173b413...

Reported-by: syzbot syzbot+69fbd3e01470f169c8c4@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/90b55ec3-d5b0-3307-9f7c-7ff5c5fd6ad3@i-love.sakura... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/video/fbdev/vga16fb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/vga16fb.c b/drivers/video/fbdev/vga16fb.c index a20eeb8308ff..578d3541e3d6 100644 --- a/drivers/video/fbdev/vga16fb.c +++ b/drivers/video/fbdev/vga16fb.c @@ -1121,7 +1121,7 @@ static void vga_8planes_imageblit(struct fb_info *info, const struct fb_image *i char oldop = setop(0); char oldsr = setsr(0); char oldmask = selectmask(); - const char *cdat = image->data; + const unsigned char *cdat = image->data; u32 dx = image->dx; char __iomem *where; int y;