ext4: check for NUL characters in extended attribute's name
authorTheodore Ts'o <tytso@mit.edu>
Wed, 1 Aug 2018 16:36:52 +0000 (12:36 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Sep 2018 07:20:06 +0000 (09:20 +0200)
commit9c2860f4564dfea57bbd670f3ecaf326b57180c1
treef3afcf632a889ec25572a45da0bc91b896bdac87
parent1ad409840b14eedd28d4e057e028515027c03aa1
ext4: check for NUL characters in extended attribute's name

commit 7d95178c77014dbd8dce36ee40bbbc5e6c121ff5 upstream.

Extended attribute names are defined to be NUL-terminated, so the name
must not contain a NUL character.  This is important because there are
places when remove extended attribute, the code uses strlen to
determine the length of the entry.  That should probably be fixed at
some point, but code is currently really messy, so the simplest fix
for now is to simply validate that the extended attributes are sane.

https://bugzilla.kernel.org/show_bug.cgi?id=200401

Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/ext4/xattr.c