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 B8BF7258EF3 for ; Tue, 8 Sep 2026 01:05:48 +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=1788829550; cv=none; b=m85SlTzpcsVNjOnJ+rxEQmxlItUY51dmemnL4dUlplzlvpP3iGucSLcBGWUgUbJEuBZvhQOobp3Y/zNb13Honx2KhV1N1qtLntMACqLkkRdXt2lhupYHmB3SA2JQuO0veCNOVzmaUVgf7b5MbmBIwYTmTjrLCTtWsSOcF3Q3BmE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788829550; c=relaxed/simple; bh=cWY+uaejsE+BB7W4oA1tJwWTeEO+kezkcjzAJS1vkwY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TrX/DhoXMF2C2kaa54EuUioFzrdOBFo35fQrHOa/Q3yayh4fgiCxV+k6jhMDUkMXTfBNkhY+kumXEt1V4U+UnGqjVnCzo1x33gcsVyrxs7vy2mIGsKzMn4+uuJpu1xXcbkLsyd6VP7G0pYhCKL2Exkb1ciw90371hQOG6rWxs/4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iax//Q2i; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iax//Q2i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE9601F00A3E; Tue, 8 Sep 2026 01:05:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788829548; bh=vPBTkhUnnsvAUjIyKGJ5buJxqrmwqNVK8GFgx8LwgCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=iax//Q2ijbfXU1c73NpTy6KMq/ItC5r26xKpGMBECjXvRi8MAUm4fupdX9SFQ+Kio uUo7KB7nYNWdYeNSlx0XqoNA0w2IiveTdhHVohQ3zfjezUdsx9oJKKd1tgoaNSIXVl sLvCarBON8aLO/41hij/2AmO0+zHBS7KJJKD9S2R1Iem6+Nb+v8Yd/XeuUMMQ4c0Ud ah3qyeXnl5g9os6HqNoIn7VrlKh6Ztm4Q5Gxa22KuMbVE+ymwJvqip2aqEImU5j1qV Vs63otuRsdhgq8zUBjZdoSrbkPwshmJEwkxdbXG3toBIqYfXbMg1BhDTLohD6kwSY4 /1LJGYriEgw+g== From: Sasha Levin To: stable@vger.kernel.org Cc: Thomas Zimmermann , Sui Jingfeng , Javier Martinez Canillas , Helge Deller , Sasha Levin Subject: [PATCH 6.1.y 2/5] fbdev: Validate info->screen_{base, buffer} in fb_ops implementations Date: Mon, 7 Sep 2026 21:05:42 -0400 Message-ID: <20260908010545.1675830-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260908010545.1675830-1-sashal@kernel.org> References: <2026090350-babble-bobbing-7765@gregkh> <20260908010545.1675830-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Thomas Zimmermann [ Upstream commit 3f8974f68f408f4983443b745a3cf95b06112469 ] Push the test for info->screen_base from fb_read() and fb_write() into the implementations of struct fb_ops.{fb_read,fb_write}. In cases where the driver operates on info->screen_buffer, test this field instead. While bothi fields, screen_base and screen_buffer, are stored in the same location, they refer to different address spaces. For correctness, we want to test each field in exactly the code that uses it. v2: * also test screen_base in pvr2fb (Geert) * also test screen_buffer in ivtvfb, arcfb, broadsheetfb, hecubafb, metronomefb and ssd1307fb (Geert) * give a rational for the change (Geert) Signed-off-by: Thomas Zimmermann Tested-by: Sui Jingfeng Reviewed-by: Javier Martinez Canillas Acked-by: Helge Deller Link: https://patchwork.freedesktop.org/patch/msgid/20230428122452.4856-18-tzimmermann@suse.de Stable-dep-of: 9ad709afdfa3 ("fbdev: ssd1307fb: defer I2C transfers from damage callbacks") Signed-off-by: Sasha Levin --- drivers/media/pci/ivtv/ivtvfb.c | 3 +++ drivers/video/fbdev/arcfb.c | 3 +++ drivers/video/fbdev/broadsheetfb.c | 3 +++ drivers/video/fbdev/cobalt_lcdfb.c | 6 ++++++ drivers/video/fbdev/core/fb_sys_fops.c | 6 ++++++ drivers/video/fbdev/core/fbmem.c | 10 ++++++++-- drivers/video/fbdev/hecubafb.c | 3 +++ drivers/video/fbdev/metronomefb.c | 3 +++ drivers/video/fbdev/pvr2fb.c | 3 +++ drivers/video/fbdev/sm712fb.c | 4 ++-- drivers/video/fbdev/ssd1307fb.c | 3 +++ 11 files changed, 43 insertions(+), 4 deletions(-) diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c index 23e6cc5172d7f..19f5abd06907e 100644 --- a/drivers/media/pci/ivtv/ivtvfb.c +++ b/drivers/media/pci/ivtv/ivtvfb.c @@ -378,6 +378,9 @@ static ssize_t ivtvfb_write(struct fb_info *info, const char __user *buf, unsigned long dma_size; u16 lead = 0, tail = 0; + if (!info->screen_base) + return -ENODEV; + total_size = info->screen_size; if (total_size == 0) diff --git a/drivers/video/fbdev/arcfb.c b/drivers/video/fbdev/arcfb.c index 024d0ee4f04f9..69a6cda61cebe 100644 --- a/drivers/video/fbdev/arcfb.c +++ b/drivers/video/fbdev/arcfb.c @@ -451,6 +451,9 @@ static ssize_t arcfb_write(struct fb_info *info, const char __user *buf, struct arcfb_par *par; unsigned int xres; + if (!info->screen_buffer) + return -ENODEV; + p = *ppos; par = info->par; xres = info->var.xres; diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c index c694ab918978f..4c6c42e2d32f7 100644 --- a/drivers/video/fbdev/broadsheetfb.c +++ b/drivers/video/fbdev/broadsheetfb.c @@ -1013,6 +1013,9 @@ static ssize_t broadsheetfb_write(struct fb_info *info, const char __user *buf, int err = 0; unsigned long total_size; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->fix.smem_len; if (p > total_size) diff --git a/drivers/video/fbdev/cobalt_lcdfb.c b/drivers/video/fbdev/cobalt_lcdfb.c index 5f8b6324d2e8c..26dbd1c78195c 100644 --- a/drivers/video/fbdev/cobalt_lcdfb.c +++ b/drivers/video/fbdev/cobalt_lcdfb.c @@ -129,6 +129,9 @@ static ssize_t cobalt_lcdfb_read(struct fb_info *info, char __user *buf, unsigned long pos; int len, retval = 0; + if (!info->screen_base) + return -ENODEV; + pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; @@ -175,6 +178,9 @@ static ssize_t cobalt_lcdfb_write(struct fb_info *info, const char __user *buf, unsigned long pos; int len, retval = 0; + if (!info->screen_base) + return -ENODEV; + pos = *ppos; if (pos >= LCD_CHARS_MAX || count == 0) return 0; diff --git a/drivers/video/fbdev/core/fb_sys_fops.c b/drivers/video/fbdev/core/fb_sys_fops.c index facf47a69483c..432fa3fa7fa13 100644 --- a/drivers/video/fbdev/core/fb_sys_fops.c +++ b/drivers/video/fbdev/core/fb_sys_fops.c @@ -21,6 +21,9 @@ ssize_t fb_sys_read(struct fb_info *info, char __user *buf, size_t count, int err = 0; unsigned long total_size; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->screen_size; if (total_size == 0) @@ -58,6 +61,9 @@ ssize_t fb_sys_write(struct fb_info *info, const char __user *buf, int err = 0; unsigned long total_size; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->screen_size; if (total_size == 0) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index bd0be854b1161..a43812a2dfec7 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -768,7 +768,7 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) int c, cnt = 0, err = 0; unsigned long total_size; - if (!info || ! info->screen_base) + if (!info) return -ENODEV; if (info->state != FBINFO_STATE_RUNNING) @@ -777,6 +777,9 @@ fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) if (info->fbops->fb_read) return info->fbops->fb_read(info, buf, count, ppos); + if (!info->screen_base) + return -ENODEV; + total_size = info->screen_size; if (total_size == 0) @@ -833,7 +836,7 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) int c, cnt = 0, err = 0; unsigned long total_size; - if (!info || !info->screen_base) + if (!info) return -ENODEV; if (info->state != FBINFO_STATE_RUNNING) @@ -842,6 +845,9 @@ fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) if (info->fbops->fb_write) return info->fbops->fb_write(info, buf, count, ppos); + if (!info->screen_base) + return -ENODEV; + total_size = info->screen_size; if (total_size == 0) diff --git a/drivers/video/fbdev/hecubafb.c b/drivers/video/fbdev/hecubafb.c index f6be62ed42c5a..98e224a9641c7 100644 --- a/drivers/video/fbdev/hecubafb.c +++ b/drivers/video/fbdev/hecubafb.c @@ -163,6 +163,9 @@ static ssize_t hecubafb_write(struct fb_info *info, const char __user *buf, int err = 0; unsigned long total_size; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->fix.smem_len; if (p > total_size) diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c index 17307c00d46f0..eba185b58f0ce 100644 --- a/drivers/video/fbdev/metronomefb.c +++ b/drivers/video/fbdev/metronomefb.c @@ -523,6 +523,9 @@ static ssize_t metronomefb_write(struct fb_info *info, const char __user *buf, int err = 0; unsigned long total_size; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->fix.smem_len; if (p > total_size) diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c index 0bb464310e640..955c35352c220 100644 --- a/drivers/video/fbdev/pvr2fb.c +++ b/drivers/video/fbdev/pvr2fb.c @@ -647,6 +647,9 @@ static ssize_t pvr2fb_write(struct fb_info *info, const char *buf, struct page **pages; int ret, i; + if (!info->screen_base) + return -ENODEV; + nr_pages = (count + PAGE_SIZE - 1) >> PAGE_SHIFT; pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c index b1bccb5f83e09..88f898580a68d 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1028,7 +1028,7 @@ static ssize_t smtcfb_read(struct fb_info *info, char __user *buf, int c, i, cnt = 0, err = 0; unsigned long total_size; - if (!info || !info->screen_base) + if (!info->screen_base) return -ENODEV; total_size = info->screen_size; @@ -1091,7 +1091,7 @@ static ssize_t smtcfb_write(struct fb_info *info, const char __user *buf, int c, i, cnt = 0, err = 0; unsigned long total_size; - if (!info || !info->screen_base) + if (!info->screen_base) return -ENODEV; total_size = info->screen_size; diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index b9fefa844574e..7620c6913520a 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -301,6 +301,9 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, void *dst; int ret; + if (!info->screen_buffer) + return -ENODEV; + total_size = info->fix.smem_len; if (p > total_size) -- 2.53.0