| Message ID | 20220225035610.2552144-2-keescook@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/dp: Fix out-of-bounds reads | expand |
diff --git a/include/drm/dp/drm_dp_helper.h b/include/drm/dp/drm_dp_helper.h index 69487bd8ed56..2a0e75e69e80 100644 --- a/include/drm/dp/drm_dp_helper.h +++ b/include/drm/dp/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: Daniel Vetter <daniel@ffwll.ch> 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: 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> Link: https://lore.kernel.org/r/20220105173310.2420598-1-keescook@chromium.org --- include/drm/dp/drm_dp_helper.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)