| Message ID | 20230824085731.9930-1-coolrrsh@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] media: gspca: UBSAN: shift-out-of-bounds in set_flicker | expand |
On Thu, Aug 24, 2023 at 02:27:31PM +0530, coolrrsh@gmail.com wrote: > From: Rajeshwar R Shinde <coolrrsh@gmail.com> > > 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 int, a shift-out-of-bounds error occurs. The error is > generated when the variable "currentexp" is left-shifted by more than 31 > bits. In order to confirm the range is valid, the conditional expression > was 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> You have loads of trailing whitespace, please fix your editor to not do that. > --- > v1->v2 > Changed the patch In what way? Be specific. > v2->v3 > Changed the commit message Again, be specific please. Otherwise all changes could be listed with these two sentances and that helps none of us out :( > --- > 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; Why is this still -1? greg k-h
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; currentexp = currentexp << sd->params.exposure.gain; sd->params.exposure.gain = 0; /* round down current exposure to nearest value */