Re: [PATCH v2] fbdev: potential information leak in do_fb_ioctl()
From: Bartlomiej Zolnierkiewicz <hidden>
Date: 2020-01-15 14:31:35
Also in:
dri-devel, kernel-janitors, lkml
On 1/13/20 12:08 PM, Dan Carpenter wrote:
The "fix" struct has a 2 byte hole after ->ywrapstep and the
"fix = info->fix;" assignment doesn't necessarily clear it. It depends
on the compiler. The solution is just to replace the assignment with an
memcpy().
Fixes: 1f5e31d7e55a ("fbmem: don't call copy_from/to_user() with mutex held")
Signed-off-by: Dan Carpenter <redacted>Patch queued for v5.6, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
quoted hunk ↗ jump to hunk
--- v2: Use memcpy() drivers/video/fbdev/core/fbmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index d04554959ea7..bb8d8dbc0461 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c@@ -1115,7 +1115,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, break; case FBIOGET_FSCREENINFO: lock_fb_info(info); - fix = info->fix; + memcpy(&fix, &info->fix, sizeof(fix)); if (info->flags & FBINFO_HIDE_SMEM_START) fix.smem_start = 0; unlock_fb_info(info);