fs/xattr.c: zero out memory copied to userspace in getxattr

getxattr uses vmalloc to allocate memory if kzalloc fails.  This is filled
by vfs_getxattr and then copied to the userspace.  vmalloc, however,
doesn't zero out the memory so if the specific implementation of the xattr
handler is sloppy we can theoretically expose a kernel memory.  There is
no real sign this is really the case but let's make sure this will not
happen and use vzalloc instead.

Fixes: 779302e67835 ("fs/xattr.c:getxattr(): improve handling of allocation failures")
Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions