Messages in this thread Patch in this message | | | Subject | [PATCH] drivers/media/video/ivtv/ivtvfb.c: prevent reading uninitialized stack memory | From | Dan Rosenberg <> | Date | Wed, 15 Sep 2010 17:44:22 -0400 |
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The FBIOGET_VBLANK device ioctl allows unprivileged users to read 16 bytes of uninitialized stack memory, because the "reserved" member of the fb_vblank struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it.
Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
--- linux-2.6.35.4.orig/drivers/media/video/ivtv/ivtvfb.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/media/video/ivtv/ivtvfb.c 2010-09-15 14:16:46.797375399 -0400 @@ -458,6 +458,8 @@ static int ivtvfb_ioctl(struct fb_info * struct fb_vblank vblank; u32 trace; + memset(&vblank, 0, sizeof(struct fb_vblank)); + vblank.flags = FB_VBLANK_HAVE_COUNT |FB_VBLANK_HAVE_VCOUNT | FB_VBLANK_HAVE_VSYNC; trace = read_reg(IVTV_REG_DEC_LINE_FIELD) >> 16;
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