[PATCH 4.4 054/104] omap2fb: Fix stack memory disclosure

From: Greg Kroah-Hartman
Date: Thu Jan 24 2019 - 14:26:17 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: Vlad Tsyrklevich <vlad@xxxxxxxxxxxxxxx>

commit a01421e4484327fe44f8e126793ed5a48a221e24 upstream.

Using [1] for static analysis I found that the OMAPFB_QUERY_PLANE,
cases could all leak uninitialized stack memory--either due to
uninitialized padding or 'reserved' fields.

Fix them by clearing the shared union used to store copied out data.

[1] https://github.com/vlad902/kernel-uninitialized-memory-checker

Signed-off-by: Vlad Tsyrklevich <vlad@xxxxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Fixes: b39a982ddecf ("OMAP: DSS2: omapfb driver")
Cc: security@xxxxxxxxxx
[b.zolnierkie: prefix patch subject with "omap2fb: "]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
@@ -609,6 +609,8 @@ int omapfb_ioctl(struct fb_info *fbi, un

int r = 0;

+ memset(&p, 0, sizeof(p));
switch (cmd) {
DBG("ioctl SYNC_GFX\n");