From aac5574ff340a665ccc78d4c3d61596ac67acbbe Mon Sep 17 00:00:00 2001 From: Darren Kenny Date: Fri, 4 Dec 2020 14:51:30 +0000 Subject: [PATCH] video/fb/video_fb: Fix possible integer overflow It is minimal possibility that the values being used here will overflow. So, change the code to use the safemath function grub_mul() to ensure that doesn't happen. Fixes: CID 73761 Signed-off-by: Darren Kenny Reviewed-by: Daniel Kiper Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=08413f2f4edec0e2d9bf15f836f6ee5ca2e379cb] Signed-off-by: Marta Rybczynska --- grub-core/video/fb/video_fb.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/grub-core/video/fb/video_fb.c b/grub-core/video/fb/video_fb.c index 1c9a138..ae6b89f 100644 --- a/grub-core/video/fb/video_fb.c +++ b/grub-core/video/fb/video_fb.c @@ -1537,7 +1537,13 @@ doublebuf_pageflipping_init (struct grub_video_mode_info *mode_info, volatile void *page1_ptr) { grub_err_t err; - grub_size_t page_size = mode_info->pitch * mode_info->height; + grub_size_t page_size = 0; + + if (grub_mul (mode_info->pitch, mode_info->height, &page_size)) + { + /* Shouldn't happen, but if it does we've a bug. */ + return GRUB_ERR_BUG; + } framebuffer.offscreen_buffer = grub_malloc (page_size); if (! framebuffer.offscreen_buffer)