| Message ID | 20230515123818.93971-1-raphael.gallais-pou@foss.st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND] drm/stm: ltdc: fix late dereference check | expand |
On 5/15/23 14:38, Raphael Gallais-Pou wrote: > In ltdc_crtc_set_crc_source(), struct drm_crtc was dereferenced in a > container_of() before the pointer check. This could cause a kernel panic. > > Fix this smatch warning: > drivers/gpu/drm/stm/ltdc.c:1124 ltdc_crtc_set_crc_source() warn: variable dereferenced before check 'crtc' (see line 1119) > > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <error27@gmail.com> > Link: https://lore.kernel.org/lkml/202212241802.zeLFZCXB-lkp@intel.com/ > Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> > --- > drivers/gpu/drm/stm/ltdc.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c > index 03c6becda795..b8be4c1db423 100644 > --- a/drivers/gpu/drm/stm/ltdc.c > +++ b/drivers/gpu/drm/stm/ltdc.c > @@ -1145,7 +1145,7 @@ static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc) > > static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) > { > - struct ltdc_device *ldev = crtc_to_ltdc(crtc); > + struct ltdc_device *ldev; > int ret; > > DRM_DEBUG_DRIVER("\n"); > @@ -1153,6 +1153,8 @@ static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) > if (!crtc) > return -ENODEV; > > + ldev = crtc_to_ltdc(crtc); > + > if (source && strcmp(source, "auto") == 0) { > ldev->crc_active = true; > ret = regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN); Hi Raphael, and many thanks for your patch. Acked-by: Philippe Cornu <philippe.cornu@foss.st.com> Philippe :-)
On 5/15/23 14:38, Raphael Gallais-Pou wrote: > In ltdc_crtc_set_crc_source(), struct drm_crtc was dereferenced in a > container_of() before the pointer check. This could cause a kernel panic. > > Fix this smatch warning: > drivers/gpu/drm/stm/ltdc.c:1124 ltdc_crtc_set_crc_source() warn: variable dereferenced before check 'crtc' (see line 1119) > > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <error27@gmail.com> > Link: https://lore.kernel.org/lkml/202212241802.zeLFZCXB-lkp@intel.com/ > Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> > --- > drivers/gpu/drm/stm/ltdc.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c > index 03c6becda795..b8be4c1db423 100644 > --- a/drivers/gpu/drm/stm/ltdc.c > +++ b/drivers/gpu/drm/stm/ltdc.c > @@ -1145,7 +1145,7 @@ static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc) > > static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) > { > - struct ltdc_device *ldev = crtc_to_ltdc(crtc); > + struct ltdc_device *ldev; > int ret; > > DRM_DEBUG_DRIVER("\n"); > @@ -1153,6 +1153,8 @@ static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) > if (!crtc) > return -ENODEV; > > + ldev = crtc_to_ltdc(crtc); > + > if (source && strcmp(source, "auto") == 0) { > ldev->crc_active = true; > ret = regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN); Hi Raphael, Applied on drm-misc-next. Note & fyi, I fixed the following warning, please be sure to follow this rule next time :-) WARNING:BAD_REPORTED_BY_LINK: Reported-by: should be immediately followed by Closes: with a URL to the report Many thanks for your patch, Philippe :-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 03c6becda795..b8be4c1db423 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -1145,7 +1145,7 @@ static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc) static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) { - struct ltdc_device *ldev = crtc_to_ltdc(crtc); + struct ltdc_device *ldev; int ret; DRM_DEBUG_DRIVER("\n"); @@ -1153,6 +1153,8 @@ static int ltdc_crtc_set_crc_source(struct drm_crtc *crtc, const char *source) if (!crtc) return -ENODEV; + ldev = crtc_to_ltdc(crtc); + if (source && strcmp(source, "auto") == 0) { ldev->crc_active = true; ret = regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_CRCEN);
In ltdc_crtc_set_crc_source(), struct drm_crtc was dereferenced in a container_of() before the pointer check. This could cause a kernel panic. Fix this smatch warning: drivers/gpu/drm/stm/ltdc.c:1124 ltdc_crtc_set_crc_source() warn: variable dereferenced before check 'crtc' (see line 1119) Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <error27@gmail.com> Link: https://lore.kernel.org/lkml/202212241802.zeLFZCXB-lkp@intel.com/ Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> --- drivers/gpu/drm/stm/ltdc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)