| Message ID | 20220105173310.2420598-1-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 280862eb95940617751900b0332264b5a0908783 |
| Headers | show |
| Series | [v2] drm/dp: Fix off-by-one in register cache size | expand |
Ping. This is a OOB read fix. Can something send this to Linus please? -Kees On Wed, Jan 05, 2022 at 09:33:10AM -0800, Kees Cook wrote: > The pcon_dsc_dpcd array holds 13 registers (0x92 through 0x9E). Fix the > math to calculate the max size. Found from a -Warray-bounds build: > > drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_pcon_dsc_bpp_incr': > drivers/gpu/drm/drm_dp_helper.c:3130:28: error: array subscript 12 is outside array bounds of 'const u8[12]' {aka 'const unsigned char[12]'} [-Werror=array-bounds] > 3130 | buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER]; > | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/gpu/drm/drm_dp_helper.c:3126:39: note: while referencing 'pcon_dsc_dpcd' > 3126 | int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) > | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> > Cc: Maxime Ripard <mripard@kernel.org> > Cc: Thomas Zimmermann <tzimmermann@suse.de> > Cc: David Airlie <airlied@linux.ie> > Cc: Daniel Vetter <daniel@ffwll.ch> > Cc: dri-devel@lists.freedesktop.org > Fixes: e2e16da398d9 ("drm/dp_helper: Add support for Configuring DSC for HDMI2.1 Pcon") > Cc: stable@vger.kernel.org > Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> > Link: https://lore.kernel.org/lkml/20211214001849.GA62559@embeddedor/ > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > v1: https://lore.kernel.org/lkml/20211203084333.3105038-1-keescook@chromium.org/ > v2: > - add reviewed-by > - add cc:stable > --- > include/drm/drm_dp_helper.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index 30359e434c3f..472dac376284 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -456,7 +456,7 @@ struct drm_panel; > #define DP_FEC_CAPABILITY_1 0x091 /* 2.0 */ > > /* DP-HDMI2.1 PCON DSC ENCODER SUPPORT */ > -#define DP_PCON_DSC_ENCODER_CAP_SIZE 0xC /* 0x9E - 0x92 */ > +#define DP_PCON_DSC_ENCODER_CAP_SIZE 0xD /* 0x92 through 0x9E */ > #define DP_PCON_DSC_ENCODER 0x092 > # define DP_PCON_DSC_ENCODER_SUPPORTED (1 << 0) > # define DP_PCON_DSC_PPS_ENC_OVERRIDE (1 << 1) > -- > 2.30.2 >
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 30359e434c3f..472dac376284 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -456,7 +456,7 @@ struct drm_panel; #define DP_FEC_CAPABILITY_1 0x091 /* 2.0 */ /* DP-HDMI2.1 PCON DSC ENCODER SUPPORT */ -#define DP_PCON_DSC_ENCODER_CAP_SIZE 0xC /* 0x9E - 0x92 */ +#define DP_PCON_DSC_ENCODER_CAP_SIZE 0xD /* 0x92 through 0x9E */ #define DP_PCON_DSC_ENCODER 0x092 # define DP_PCON_DSC_ENCODER_SUPPORTED (1 << 0) # define DP_PCON_DSC_PPS_ENC_OVERRIDE (1 << 1)
The pcon_dsc_dpcd array holds 13 registers (0x92 through 0x9E). Fix the math to calculate the max size. Found from a -Warray-bounds build: drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_pcon_dsc_bpp_incr': drivers/gpu/drm/drm_dp_helper.c:3130:28: error: array subscript 12 is outside array bounds of 'const u8[12]' {aka 'const unsigned char[12]'} [-Werror=array-bounds] 3130 | buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER]; | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/drm_dp_helper.c:3126:39: note: while referencing 'pcon_dsc_dpcd' 3126 | int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE]) | ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Fixes: e2e16da398d9 ("drm/dp_helper: Add support for Configuring DSC for HDMI2.1 Pcon") Cc: stable@vger.kernel.org Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/lkml/20211214001849.GA62559@embeddedor/ Signed-off-by: Kees Cook <keescook@chromium.org> --- v1: https://lore.kernel.org/lkml/20211203084333.3105038-1-keescook@chromium.org/ v2: - add reviewed-by - add cc:stable --- include/drm/drm_dp_helper.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)