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authorDan Carpenter <dan.carpenter@oracle.com>2020-01-13 14:08:14 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-04-23 10:38:23 +0200
commitde095fa19cacd22760e74b5f5e1321c0b4c45d39 (patch)
treee404088455b3003aff476c3d5bf3e357624c57f9
parent4b041c16eef495af3a6256f4f2f097ead5605336 (diff)
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fbdev: potential information leak in do_fb_ioctl()
commit d3d19d6fc5736a798b118971935ce274f7deaa82 upstream. 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> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andrea Righi <righi.andrea@gmail.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Peter Rosin <peda@axentia.se> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200113100132.ixpaymordi24n3av@kili.mountain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/video/fbdev/core/fbmem.c2
1 files changed, 1 insertions, 1 deletions
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);