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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id b17-20020a056a000a9100b004e1b7cdb8fdsm1058315pfl.70.2022.02.24.19.56.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Feb 2022 19:56:14 -0800 (PST) From: Kees Cook To: Daniel Vetter Cc: Kees Cook , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , dri-devel@lists.freedesktop.org, stable@vger.kernel.org, "Gustavo A . R . Silva" , Jani Nikula , Thierry Reding , Jonathan Hunter , Lyude Paul , =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= , Dave Airlie , Douglas Anderson , Ankit Nautiyal , Uma Shankar , Philipp Zabel , linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v3 1/2] drm/dp: Fix off-by-one in register cache size Date: Thu, 24 Feb 2022 19:56:09 -0800 Message-Id: <20220225035610.2552144-2-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220225035610.2552144-1-keescook@chromium.org> References: <20220225035610.2552144-1-keescook@chromium.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2186; h=from:subject; bh=XnOsDK/+y5ut9JOHl+TySo3UIYwEhWHbEO6qaNRWGSY=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBiGFNZW/hRfwrRCOANpF+kIRDX8smczwuFLS61jR5x Go4dvSGJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYhhTWQAKCRCJcvTf3G3AJovDD/ 4yUTMY28Mu3JJTBRXMY90Hwl/Lk8weWvE5upj/7BL/Ska+gAQoQJoEy1CvFmOr/qZ7HYAvGC7Y1meE aix4GNRbGGBCyXTajDyr0+52/U6mOJie3uoOvDtEZM25Uu/2xfHJQF/sUMgnNAfpgmdMZ96VcTTgd9 NLHu72Fg8wGY0TPxf5L/qX8hPQ3I/iMYh3olD1hH1UvaAG+Y2jY17o1P3n6DNuk2BYfomdDTEBbTrJ JnEhtvp1QDXGUMm8FzoxsKQx3u6cZveroMSL03TtuxU9zU+WFZhjZpUbNjzx/1PeY6YHIpA4whU9Ny 8vjW9A/kA8B7w8Kb6gK0ii8l2PpC3Dpx7S7nCXxqUwie19Ao2s5HII4wQAQm/dUTHEpNeGGf18iYUw kOLvwDmKTfNqqKYICXhmTB48qmYBRHIE1yJub5tsfc7+FvIY0UtwJEsaQLObUvWP1AU7LI1KJybv65 y1vTNTiiZ7IrCg0GgreFQ6Zil6IVniHPmGCFBAhd0Z+xP7UX8dU3Blminv/hZVi35o84bny+qeDybp bBXASiW8AadMr7Z79vtunngz2zsRrRP8R0L2tPV+bwDG36AhArVrlKhMpiAxjbTEDHKMjwglkdKoB2 wpyFMtu3uHSjyi0moyYrG9s19iR3UXMSJJA76tTiUI3uC7wBW8LV3eJNV9tQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie 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 Link: https://lore.kernel.org/lkml/20211214001849.GA62559@embeddedor/ Signed-off-by: Kees Cook 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(-) 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)