Blame SOURCES/0418-video-fb-video_fb-Fix-possible-integer-overflow.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Darren Kenny <darren.kenny@oracle.com>
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Date: Fri, 4 Dec 2020 14:51:30 +0000
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Subject: [PATCH] video/fb/video_fb: Fix possible integer overflow
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It is minimal possibility that the values being used here will overflow.
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So, change the code to use the safemath function grub_mul() to ensure
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that doesn't happen.
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Fixes: CID 73761
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Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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---
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 grub-core/video/fb/video_fb.c | 8 +++++++-
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 1 file changed, 7 insertions(+), 1 deletion(-)
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diff --git a/grub-core/video/fb/video_fb.c b/grub-core/video/fb/video_fb.c
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index 1c9a138dc..ae6b89f9a 100644
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--- a/grub-core/video/fb/video_fb.c
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+++ b/grub-core/video/fb/video_fb.c
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@@ -1537,7 +1537,13 @@ doublebuf_pageflipping_init (struct grub_video_mode_info *mode_info,
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 			     volatile void *page1_ptr)
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 {
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   grub_err_t err;
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-  grub_size_t page_size = mode_info->pitch * mode_info->height;
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+  grub_size_t page_size = 0;
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+
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+  if (grub_mul (mode_info->pitch, mode_info->height, &page_size))
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+    {
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+      /* Shouldn't happen, but if it does we've a bug. */
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+      return GRUB_ERR_BUG;
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+    }
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   framebuffer.offscreen_buffer = grub_malloc (page_size);
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   if (! framebuffer.offscreen_buffer)