Commit 390c7653 authored Feb 20, 2019 by Eric Biggers Committed by Greg Kroah-Hartman Feb 27, 2019

KEYS: user: Align the payload buffer



commit cc1780fc42c76c705dd07ea123f1143dc5057630 upstream.

Align the payload of "user" and "logon" keys so that users of the
keyrings service can access it as a struct that requires more than
2-byte alignment.  fscrypt currently does this which results in the read
of fscrypt_key::size being misaligned as it needs 4-byte alignment.

Align to __alignof__(u64) rather than __alignof__(long) since in the
future it's conceivable that people would use structs beginning with
u64, which on some platforms would require more than 'long' alignment.

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Fixes: 2aa349f6 ("[PATCH] Keys: Export user-defined keyring operations")
Fixes: 88bd6ccd ("ext4 crypto: add encryption key management facilities")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 293f2dcd

include/keys/user-type.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -31,7 +31,7 @@
		struct user_key_payload {
		struct rcu_head rcu; /* RCU destructor */
		unsigned short datalen; /* length of this data */
		char data[0]; /* actual data */
		char data[0] __aligned(__alignof__(u64)); /* actual data */
		};

		extern struct key_type key_type_user;