This is a note to let you know that I've just added the patch titled
media: gspca: cpia1: shift-out-of-bounds in set_flicker
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-gspca-cpia1-shift-out-of-bounds-in-set_flicker.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f4864e428d2df7746d81de2aacc9b27053dc2265
Author: Rajeshwar R Shinde <coolrrsh@xxxxxxxxx>
Date: Wed Aug 30 13:14:01 2023 +0530
media: gspca: cpia1: shift-out-of-bounds in set_flicker
[ Upstream commit 099be1822d1f095433f4b08af9cc9d6308ec1953 ]
Syzkaller reported the following issue:
UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27
shift exponent 245 is too large for 32-bit type 'int'
When the value of the variable "sd->params.exposure.gain" exceeds the
number of bits in an integer, a shift-out-of-bounds error is reported. It
is triggered because the variable "currentexp" cannot be left-shifted by
more than the number of bits in an integer. In order to avoid invalid
range during left-shift, the conditional expression is added.
Reported-by: syzbot+e27f3dbdab04e43b9f73@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/all/20230818164522.12806-1-coolrrsh@xxxxxxxxx
Link: https://syzkaller.appspot.com/bug?extid=e27f3dbdab04e43b9f73
Signed-off-by: Rajeshwar R Shinde <coolrrsh@xxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c
index 2b09af8865f40..5e785343528cc 100644
--- a/drivers/media/usb/gspca/cpia1.c
+++ b/drivers/media/usb/gspca/cpia1.c
@@ -28,6 +28,7 @@
#include <linux/input.h>
#include <linux/sched/signal.h>
+#include <linux/bitops.h>
#include "gspca.h"
@@ -1033,6 +1034,8 @@ static int set_flicker(struct gspca_dev *gspca_dev, int on, int apply)
sd->params.exposure.expMode = 2;
sd->exposure_status = EXPOSURE_NORMAL;
}
+ if (sd->params.exposure.gain >= BITS_PER_TYPE(currentexp))
+ return -EINVAL;
currentexp = currentexp << sd->params.exposure.gain;
sd->params.exposure.gain = 0;
/* round down current exposure to nearest value */
