On 24/08/2023 09:13, Greg KH wrote: > On Thu, Aug 24, 2023 at 12:36:30PM +0530, coolrrsh@xxxxxxxxx wrote: >> From: Rajeshwar R Shinde <coolrrsh@xxxxxxxxx> >> >> 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' >> >> shift-out-of-bounds error was triggered when variable >> 'sd->params.exposure.gain' is greater than the number of bits of int. >> When the variable 'currentexp' is left shifted beyond 31 bits then >> the error is produced. Therefore added the conditional expression to >> verify valid range. >> >> Tested via syzbot. >> >> 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> > > Please do not have blank lines beween these tags. > > You also have trailing whitespace in your changelog text :( And please mention the driver name in your subject! E.g. something like: "media: gspca/cpia1: UBSAN: shift-out-of-bounds in set_flicker" That way I can actually know that this is a patch for a driver that I maintain. Regards, Hans > >> --- >> v1->v2 >> changed the patch >> changed commit message and tested with checkpatch >> >> --- >> drivers/media/usb/gspca/cpia1.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c >> index 46ed95483e22..dafc522d5e7b 100644 >> --- a/drivers/media/usb/gspca/cpia1.c >> +++ b/drivers/media/usb/gspca/cpia1.c >> @@ -1028,6 +1028,8 @@ 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 > 31) >> + return -1; > > Do not make up error codes, please return a valid one and not a random > negative number. Unless -1 is a valid value for this function? > > thanks, > > greg k-h
