| Message ID | 20241211122026.797511-1-karprzy7@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: zynqmp_dp: Fix integer overflow in zynqmp_dp_rate_get() | expand |
On Wed, 11 Dec 2024 at 13:59, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Karol, > > Thank you for the patch. > > On Wed, Dec 11, 2024 at 01:20:26PM +0100, Karol Przybylski wrote: > > This patch fixes a potential integer overflow in the zynqmp_dp_rate_get() function. > > > > The issue comes up when the expression drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000 is evaluated using 32-bit arithmetic. > > Please wrap your commit message text to 82 columns. > > > > > Now the constant is casted to compatible u64 type. > > > > Resolves CID 1636340 and CID 1635811 > > > > Does this need a Fixes: tag ? How about 'Cc: stable@vger.kernel.org' to > get it backported to stable kernels ? Thanks for the feedback, I'll add it. > > > Signed-off-by: Karol Przybylski <karprzy7@gmail.com> > > --- > > drivers/gpu/drm/xlnx/zynqmp_dp.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c > > index 25c5dc61e..55e92344b 100644 > > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > > @@ -2190,7 +2190,7 @@ static int zynqmp_dp_rate_get(void *data, u64 *val) > > struct zynqmp_dp *dp = data; > > > > mutex_lock(&dp->lock); > > - *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000; > > + *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * (u64)10000; > > You can also make the integer a 64-bit constant with > > *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000ULL; > > > mutex_unlock(&dp->lock); > > return 0; > > } It does look better. I will send v2 of this patch. > > -- > Regards, > > Laurent Pinchart
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 25c5dc61e..55e92344b 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -2190,7 +2190,7 @@ static int zynqmp_dp_rate_get(void *data, u64 *val) struct zynqmp_dp *dp = data; mutex_lock(&dp->lock); - *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000; + *val = drm_dp_bw_code_to_link_rate(dp->test.bw_code) * (u64)10000; mutex_unlock(&dp->lock); return 0; }
This patch fixes a potential integer overflow in the zynqmp_dp_rate_get() function. The issue comes up when the expression drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000 is evaluated using 32-bit arithmetic. Now the constant is casted to compatible u64 type. Resolves CID 1636340 and CID 1635811 Signed-off-by: Karol Przybylski <karprzy7@gmail.com> --- drivers/gpu/drm/xlnx/zynqmp_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)