From: Eric Biggers ebiggers@google.com

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: 2aa349f6e37c ("[PATCH] Keys: Export user-defined keyring operations") Fixes: 88bd6ccdcdd6 ("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 ---

include/keys/user-type.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/keys/user-type.h b/include/keys/user-type.h index e098cbe27db5..12babe991594 100644 --- a/include/keys/user-type.h +++ b/include/keys/user-type.h @@ -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;