FAILED: patch "[PATCH] drm/sysfb: simpledrm: Improve framebuffer-size validation" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] drm/sysfb: simpledrm: Improve framebuffer-size validation" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 03f1a3545b721fa7fdadd00080e237519a286a97
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090919-cross-finalize-0ac3@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 03f1a3545b721fa7fdadd00080e237519a286a97 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Thu, 25 Jun 2026 11:39:33 +0200
Subject: [PATCH] drm/sysfb: simpledrm: Improve framebuffer-size validation

Validate the framebuffer size from the firmware against the
limitations of struct drm_display_mode. The type only stores sizes
in 16-bit fields. Fail probing on errors.

v2:
- remove unused function simplefb_get_validated_int0() (Sashiko)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Cc: <stable@vger.kernel.org> # v5.14+
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Link: https://patch.msgid.link/20260625094509.157581-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/sysfb/simpledrm.c b/drivers/gpu/drm/sysfb/simpledrm.c
index fc168920f2c6..15dcafa9d524 100644
--- a/drivers/gpu/drm/sysfb/simpledrm.c
+++ b/drivers/gpu/drm/sysfb/simpledrm.c
@@ -48,13 +48,6 @@ simplefb_get_validated_int(struct drm_device *dev, const char *name,
 	return drm_sysfb_get_validated_int(dev, name, value, INT_MAX);
 }
 
-static int
-simplefb_get_validated_int0(struct drm_device *dev, const char *name,
-			    uint32_t value)
-{
-	return drm_sysfb_get_validated_int0(dev, name, value, INT_MAX);
-}
-
 static const struct drm_format_info *
 simplefb_get_validated_format(struct drm_device *dev, const char *format_name)
 {
@@ -88,14 +81,14 @@ static int
 simplefb_get_width_pd(struct drm_device *dev,
 		      const struct simplefb_platform_data *pd)
 {
-	return simplefb_get_validated_int0(dev, "width", pd->width);
+	return drm_sysfb_get_validated_int0(dev, "width", pd->width, U16_MAX);
 }
 
 static int
 simplefb_get_height_pd(struct drm_device *dev,
 		       const struct simplefb_platform_data *pd)
 {
-	return simplefb_get_validated_int0(dev, "height", pd->height);
+	return drm_sysfb_get_validated_int0(dev, "height", pd->height, U16_MAX);
 }
 
 static int
@@ -144,7 +137,7 @@ simplefb_get_width_of(struct drm_device *dev, struct device_node *of_node)
 
 	if (ret)
 		return ret;
-	return simplefb_get_validated_int0(dev, "width", width);
+	return drm_sysfb_get_validated_int0(dev, "width", width, U16_MAX);
 }
 
 static int
@@ -155,7 +148,7 @@ simplefb_get_height_of(struct drm_device *dev, struct device_node *of_node)
 
 	if (ret)
 		return ret;
-	return simplefb_get_validated_int0(dev, "height", height);
+	return drm_sysfb_get_validated_int0(dev, "height", height, U16_MAX);
 }
 
 static int

[PATCH 6.6.y 1/2] firmware: sysfb: Move bpp-depth calculation into screen_info helper

[Sasha Levin]

From: Thomas Zimmermann <tzimmermann@suse.de>

[ Upstream commit 1ce4c3aeef333be1e6290ec6d1f7891c2bfc7a1f ]

Move the calculation of the bits per pixels for screen_info into a
helper function. This will make it available to other callers besides
the firmware code.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250401094056.32904-14-tzimmermann@suse.de
Stable-dep-of: 03f1a3545b72 ("drm/sysfb: simpledrm: Improve framebuffer-size validation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/firmware/sysfb_simplefb.c   | 31 +------------------------
 drivers/video/screen_info_generic.c | 36 +++++++++++++++++++++++++++++
 include/linux/screen_info.h         |  2 ++
 3 files changed, 39 insertions(+), 30 deletions(-)

diff --git a/drivers/firmware/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c
index 74363ed7501f6..7f2307cde243a 100644
--- a/drivers/firmware/sysfb_simplefb.c
+++ b/drivers/firmware/sysfb_simplefb.c
@@ -35,36 +35,7 @@ __init bool sysfb_parse_mode(const struct screen_info *si,
 	if (type != VIDEO_TYPE_VLFB && type != VIDEO_TYPE_EFI)
 		return false;
 
-	/*
-	 * The meaning of depth and bpp for direct-color formats is
-	 * inconsistent:
-	 *
-	 *  - DRM format info specifies depth as the number of color
-	 *    bits; including alpha, but not including filler bits.
-	 *  - Linux' EFI platform code computes lfb_depth from the
-	 *    individual color channels, including the reserved bits.
-	 *  - VBE 1.1 defines lfb_depth for XRGB1555 as 16, but later
-	 *    versions use 15.
-	 *  - On the kernel command line, 'bpp' of 32 is usually
-	 *    XRGB8888 including the filler bits, but 15 is XRGB1555
-	 *    not including the filler bit.
-	 *
-	 * It's not easily possible to fix this in struct screen_info,
-	 * as this could break UAPI. The best solution is to compute
-	 * bits_per_pixel from the color bits, reserved bits and
-	 * reported lfb_depth, whichever is highest.  In the loop below,
-	 * ignore simplefb formats with alpha bits, as EFI and VESA
-	 * don't specify alpha channels.
-	 */
-	if (si->lfb_depth > 8) {
-		bits_per_pixel = max(max3(si->red_size + si->red_pos,
-					  si->green_size + si->green_pos,
-					  si->blue_size + si->blue_pos),
-				     si->rsvd_size + si->rsvd_pos);
-		bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth);
-	} else {
-		bits_per_pixel = si->lfb_depth;
-	}
+	bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
 
 	for (i = 0; i < ARRAY_SIZE(formats); ++i) {
 		const struct simplefb_format *f = &formats[i];
diff --git a/drivers/video/screen_info_generic.c b/drivers/video/screen_info_generic.c
index 64117c6367abb..900e9386ecebd 100644
--- a/drivers/video/screen_info_generic.c
+++ b/drivers/video/screen_info_generic.c
@@ -144,3 +144,39 @@ ssize_t screen_info_resources(const struct screen_info *si, struct resource *r,
 	return pos - r;
 }
 EXPORT_SYMBOL(screen_info_resources);
+
+/*
+ * The meaning of depth and bpp for direct-color formats is
+ * inconsistent:
+ *
+ *  - DRM format info specifies depth as the number of color
+ *    bits; including alpha, but not including filler bits.
+ *  - Linux' EFI platform code computes lfb_depth from the
+ *    individual color channels, including the reserved bits.
+ *  - VBE 1.1 defines lfb_depth for XRGB1555 as 16, but later
+ *    versions use 15.
+ *  - On the kernel command line, 'bpp' of 32 is usually
+ *    XRGB8888 including the filler bits, but 15 is XRGB1555
+ *    not including the filler bit.
+ *
+ * It is not easily possible to fix this in struct screen_info,
+ * as this could break UAPI. The best solution is to compute
+ * bits_per_pixel from the color bits, reserved bits and
+ * reported lfb_depth, whichever is highest.
+ */
+
+u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si)
+{
+	u32 bits_per_pixel = si->lfb_depth;
+
+	if (bits_per_pixel > 8) {
+		bits_per_pixel = max(max3(si->red_size + si->red_pos,
+					  si->green_size + si->green_pos,
+					  si->blue_size + si->blue_pos),
+				     si->rsvd_size + si->rsvd_pos);
+		bits_per_pixel = max_t(u32, bits_per_pixel, si->lfb_depth);
+	}
+
+	return bits_per_pixel;
+}
+EXPORT_SYMBOL(__screen_info_lfb_bits_per_pixel);
diff --git a/include/linux/screen_info.h b/include/linux/screen_info.h
index 6a4a3cec4638b..ab3cffbb58b7f 100644
--- a/include/linux/screen_info.h
+++ b/include/linux/screen_info.h
@@ -128,6 +128,8 @@ static inline unsigned int screen_info_video_type(const struct screen_info *si)
 
 ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num);
 
+u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si);
+
 #if defined(CONFIG_PCI)
 void screen_info_apply_fixups(void);
 struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
-- 
2.53.0

[PATCH 6.6.y 2/2] drm/sysfb: simpledrm: Improve framebuffer-size validation

[Sasha Levin]

From: Thomas Zimmermann <tzimmermann@suse.de>

[ Upstream commit 03f1a3545b721fa7fdadd00080e237519a286a97 ]

Validate the framebuffer size from the firmware against the
limitations of struct drm_display_mode. The type only stores sizes
in 16-bit fields. Fail probing on errors.

v2:
- remove unused function simplefb_get_validated_int0() (Sashiko)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Cc: <stable@vger.kernel.org> # v5.14+
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Link: https://patch.msgid.link/20260625094509.157581-2-tzimmermann@suse.de
[ adapted shared-validator changes to the existing simplefb_get_validated_int0() helper in drm/tiny/simpledrm.c. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/tiny/simpledrm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
index 30676b1073034..fa40da758213c 100644
--- a/drivers/gpu/drm/tiny/simpledrm.c
+++ b/drivers/gpu/drm/tiny/simpledrm.c
@@ -52,7 +52,7 @@ static int
 simplefb_get_validated_int0(struct drm_device *dev, const char *name,
 			    uint32_t value)
 {
-	if (!value) {
+	if (!value || value > U16_MAX) {
 		drm_err(dev, "simplefb: invalid framebuffer %s of %u\n",
 			name, value);
 		return -EINVAL;
-- 
2.53.0