From: Dan Carpenter <dan.carpenter@oracle.com>
To: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>,
Gerd Hoffmann <kraxel@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
Jani Nikula <jani.nikula@intel.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
Andrew Morton <akpm@linux-foundation.org>,
Sam Ravnborg <sam@ravnborg.org>, Peter Rosin <peda@axentia.se>,
Andrea Righi <righi.andrea@gmail.com>
Subject: [PATCH v2] fbdev: potential information leak in do_fb_ioctl()
Date: Mon, 13 Jan 2020 14:08:14 +0300 [thread overview]
Message-ID: <20200113100132.ixpaymordi24n3av@kili.mountain> (raw)
In-Reply-To: <fd4e6f01-074b-def7-7ffb-9a9197930c31@samsung.com>
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 <dan.carpenter@oracle.com>
---
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);
--
2.11.0
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next prev parent reply other threads:[~2020-01-13 11:10 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 18:23 [PATCH] fbdev: potential information leak in do_fb_ioctl() Dan Carpenter
2019-10-29 18:35 ` Joe Perches
2019-10-29 18:35 ` Joe Perches
2019-10-29 19:02 ` Eric W. Biederman
2019-10-29 19:02 ` Eric W. Biederman
2019-10-30 7:43 ` Andrea Righi
2019-10-30 7:43 ` Andrea Righi
2019-10-30 19:26 ` Eric W. Biederman
2019-10-30 19:26 ` Eric W. Biederman
2019-10-30 20:12 ` Andrea Righi
2019-10-30 20:12 ` Andrea Righi
2019-10-31 18:16 ` Joe Perches
2019-10-31 18:16 ` Joe Perches
2019-10-31 22:12 ` Eric W. Biederman
2019-10-31 22:12 ` Eric W. Biederman
2020-01-03 13:07 ` Bartlomiej Zolnierkiewicz
2020-01-13 11:08 ` Dan Carpenter [this message]
2020-01-15 14:31 ` [PATCH v2] " 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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