From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07AA253C3DB; Wed, 30 Sep 2026 17:41:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790077; cv=none; b=XdfUWLnv0344wM+nYGrr2I7NIOpw1ilcD5BIfJ6POdNC9jF4Tdko1W1UbPXfgXAXWme7GbXiZxCJvbv9hXSWLRrGsjjhim0qkefO2g4h53xzRoG9kr4PQs2rMHqX2BdycDmffRI+SkhnjYp/R87HjHur+JgTIYKcyWSm4h38unA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790790077; c=relaxed/simple; bh=RBfs6er0hDAEuLC0TYVxXvQgQB67E6bLSueW4On4db8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NzXumnBNbAEuGQjJRlcXltGkFHnRp0XJjpB5uEMMLnaG1S7Wam5aL/JR9bvcZdN91ghhhUXStuVOTcivAza3i8yplDKa7EYLMrsUkkguYsL0DAi4oLhL849OIiSQTcCrWIG0LN/AjjSgxTsk5TFKbuLncUlZ/uZrL9a6hcs3kSM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TTQigXMD; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TTQigXMD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 683151F000FF; Wed, 30 Sep 2026 17:41:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790790075; bh=SJkpbXLXaUgDZzV5Y69JBecuaHaebjPHlbZV7XSFRts=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TTQigXMDhYh4RyTXUyvjy0P15sYOy8+AIQa58kcHcx3UwUKTZSmNtm2oyKsCfx/fa XF/a25DpsW4N3LbZ4wGTzMH27p/9TYNfiXc+NfjMqOaFzL1OtxCCQwPIRfS6GMt8jI mcx8o8wtPReimit2hg+8M9UUHm1DXkgjIqe5Lf/k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Zimmermann , Thierry Reding , Maxime Ripard , Javier Martinez Canillas , Rayyan Ansari , Sasha Levin Subject: [PATCH 6.12 703/877] drm/sysfb: simpledrm: Improve panel-size validation Date: Wed, 30 Sep 2026 17:26:54 +0200 Message-ID: <20260930152429.853697035@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152414.738996857@linuxfoundation.org> References: <20260930152414.738996857@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Zimmermann [ Upstream commit 3a75a0761914d01c7362adf1f906cc1d1762c189 ] Validate the panel size from the device-tree node against the limitations of struct drm_display_mode. The type only stores sizes in 16-bit fields. Fail transparently on errors; do not warn. v3: - move comments to a more prominent place (Thierry) v2: - only use initialized values in debugging output (Sashiko) Signed-off-by: Thomas Zimmermann Reviewed-by: Thierry Reding Reviewed-by: Maxime Ripard Reviewed-by: Javier Martinez Canillas Fixes: 2a6d731a8f16 ("drm/simpledrm: Allow physical width and height configuration via panel node") Cc: Rayyan Ansari Cc: # v6.4+ Link: https://patch.msgid.link/20260625094509.157581-3-tzimmermann@suse.de Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/tiny/simpledrm.c | 49 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 46 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -212,6 +212,39 @@ simplefb_get_memory_of(struct drm_device return res; } +static int __simplefb_get_panel_size_mm_of(struct drm_device *dev, + struct device_node *of_panel_node, + const char *name) +{ + int ret; + u32 value; + + ret = of_property_read_u32(of_panel_node, name, &value); + if (ret) { + drm_dbg(dev, "simplefb: cannot parse panel %s: error %d\n", + name, ret); + return ret; + } else if (value > U16_MAX) { + drm_dbg(dev, "simplefb: panel %s of %u exceeds maximum value\n", + name, value); + return -EINVAL; + } + + return value; +} + +static int simplefb_get_panel_width_mm_of(struct drm_device *dev, + struct device_node *of_panel_node) +{ + return __simplefb_get_panel_size_mm_of(dev, of_panel_node, "width-mm"); +} + +static int simplefb_get_panel_height_mm_of(struct drm_device *dev, + struct device_node *of_panel_node) +{ + return __simplefb_get_panel_size_mm_of(dev, of_panel_node, "height-mm"); +} + /* * Simple Framebuffer device */ @@ -781,7 +814,7 @@ static struct simpledrm_device *simpledr struct simpledrm_device *sdev; struct drm_device *dev; int width, height, stride; - int width_mm = 0, height_mm = 0; + u16 width_mm = 0, height_mm = 0; struct device_node *panel_node; const struct drm_format_info *format; struct resource *res, *mem = NULL; @@ -844,8 +877,18 @@ static struct simpledrm_device *simpledr return ERR_CAST(mem); panel_node = of_parse_phandle(of_node, "panel", 0); if (panel_node) { - simplefb_read_u32_of(dev, panel_node, "width-mm", &width_mm); - simplefb_read_u32_of(dev, panel_node, "height-mm", &height_mm); + /* + * Ignore errors from parsing the physical panel + * size. Using the pre-initialized sizes of 0 will + * make drm_sysfb_mode() calculate a default physical + * size based on a resolution of 96 dpi. + */ + ret = simplefb_get_panel_width_mm_of(dev, panel_node); + if (ret > 0) + width_mm = ret; + ret = simplefb_get_panel_height_mm_of(dev, panel_node); + if (ret > 0) + height_mm = ret; of_node_put(panel_node); } } else {