This is a note to let you know that I've just added the patch titled

drm/dp: Fix off-by-one in register cache size

to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summ...

The filename of the patch is: drm-dp-fix-off-by-one-in-register-cache-size.patch and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From d4da1f27396fb1dde079447a3612f4f512caed07 Mon Sep 17 00:00:00 2001

From: Kees Cook keescook@chromium.org Date: Thu, 24 Feb 2022 19:56:09 -0800 Subject: drm/dp: Fix off-by-one in register cache size

From: Kees Cook keescook@chromium.org

commit d4da1f27396fb1dde079447a3612f4f512caed07 upstream.

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 Signed-off-by: Thierry Reding treding@nvidia.com Link: https://patchwork.freedesktop.org/patch/msgid/20220225035610.2552144-2-keesc... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/drm/drm_dp_helper.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -455,7 +455,7 @@ struct drm_panel; # define DP_FEC_BIT_ERROR_COUNT_CAP (1 << 3)

/* 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)

Patches currently in stable-queue which might be from keescook@chromium.org are

queue-5.15/stack-constrain-and-fix-stack-offset-randomization-w.patch queue-5.15/coredump-also-dump-first-pages-of-non-executable-elf-libraries.patch queue-5.15/selftests-lkdtm-add-ubsan-config.patch queue-5.15/fs-binfmt_elf-fix-at_phdr-for-unusual-elf-files.patch queue-5.15/gcc-plugins-stackleak-exactly-match-strings-instead-.patch queue-5.15/exec-force-single-empty-string-when-argv-is-empty.patch queue-5.15/drm-dp-fix-off-by-one-in-register-cache-size.patch queue-5.15/pstore-don-t-use-semaphores-in-always-atomic-context-code.patch