4.14-stable review patch. If anyone has any objections, please let me know.
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From: Rajeshwar R Shinde coolrrsh@gmail.com
[ 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@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/20230818164522.12806-1-coolrrsh@gmail.com Link: https://syzkaller.appspot.com/bug?extid=e27f3dbdab04e43b9f73 Signed-off-by: Rajeshwar R Shinde coolrrsh@gmail.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/usb/gspca/cpia1.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c index e91d00762e94b..bf34479a87cc5 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"
@@ -1032,6 +1033,8 @@ 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 */