UPSTREAM: ext4: limit xattr size to INT_MAX
commit ce3fd194fcc6fbdc00ce095a852f22df97baa401 upstream.
ext4 isn't validating the sizes of xattrs where the value of the xattr
is stored in an external inode. This is problematic because
->e_value_size is a u32, but ext4_xattr_get() returns an int. A very
large size is misinterpreted as an error code, which ext4_get_acl()
translates into a bogus ERR_PTR() for which IS_ERR() returns false,
causing a crash.
Fix this by validating that all xattrs are <= INT_MAX bytes.
This issue has been assigned CVE-2018-1095.
https://bugzilla.kernel.org/show_bug.cgi?id=199185
https://bugzilla.redhat.com/show_bug.cgi?id=1560793
Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Fixes: e50e5129f384 ("ext4: xattr-in-inode support")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
BUG=b:79190910
TEST=trybot
Change-Id: Icd480c72bb7c6eb2590f60e8660cd3eb1f6d11d6
Signed-off-by: Pradeep Sawlani <sawlani@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1044447
Reviewed-by: Guenter Roeck <groeck@chromium.org>
1 file changed
