From: Dan Carpenter <dan.carpenter@oracle.com>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Andrea Righi <righi.andrea@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>,
Sam Ravnborg <sam@ravnborg.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Peter Rosin <peda@axentia.se>, Gerd Hoffmann <kraxel@redhat.com>,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
security@kernel.org, Kees Cook <keescook@chromium.org>,
Julia Lawall <Julia.Lawall@lip6.fr>
Subject: [PATCH] fbdev: potential information leak in do_fb_ioctl()
Date: Tue, 29 Oct 2019 21:23:20 +0300 [thread overview]
Message-ID: <20191029182320.GA17569@mwanda> (raw)
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.
Fixes: 1f5e31d7e55a ("fbmem: don't call copy_from/to_user() with mutex held")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I have 13 more similar places to patch... I'm not totally sure I
understand all the issues involved.
drivers/video/fbdev/core/fbmem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 6f6fc785b545..b4ce6a28aed9 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1109,6 +1109,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
ret = -EFAULT;
break;
case FBIOGET_FSCREENINFO:
+ memset(&fix, 0, sizeof(fix));
lock_fb_info(info);
fix = info->fix;
if (info->flags & FBINFO_HIDE_SMEM_START)
--
2.20.1
next reply other threads:[~2019-10-29 18:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 18:23 Dan Carpenter [this message]
2019-10-29 18:35 ` [PATCH] fbdev: potential information leak in do_fb_ioctl() Joe Perches
2019-10-29 19:02 ` Eric W. Biederman
2019-10-30 7:43 ` Andrea Righi
2019-10-30 19:26 ` Eric W. Biederman
2019-10-30 20:12 ` Andrea Righi
2019-10-31 18:16 ` Joe Perches
2019-10-31 22:12 ` Eric W. Biederman
2020-01-03 13:07 ` Bartlomiej Zolnierkiewicz
2020-01-13 11:08 ` [PATCH v2] " Dan Carpenter
2020-01-15 14:31 ` Bartlomiej Zolnierkiewicz
2020-01-13 12:49 ` [PATCH] " Arnd Bergmann
2020-01-15 13:09 ` Bartlomiej Zolnierkiewicz
2020-01-15 13:16 ` Arnd Bergmann
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