From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Biggers Date: Thu, 07 Feb 2019 23:35:10 +0000 Subject: Re: [PATCH] KEYS: user: Align the payload buffer Message-Id: <20190207233509.GA125156@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <20190115033716.18380-1-ebiggers@kernel.org> In-Reply-To: <20190115033716.18380-1-ebiggers@kernel.org> To: keyrings@vger.kernel.org, David Howells Cc: Aaro Koskinen , linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, Jan 14, 2019 at 07:37:16PM -0800, Eric Biggers wrote: > From: Eric Biggers > > 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 > 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 > --- > 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 e098cbe27db54..12babe9915944 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; > -- > 2.20.1 > Ping. David, are you planning to apply this? - Eric From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 7 Feb 2019 15:35:10 -0800 From: Eric Biggers Subject: Re: [PATCH] KEYS: user: Align the payload buffer Message-ID: <20190207233509.GA125156@gmail.com> References: <20190115033716.18380-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190115033716.18380-1-ebiggers@kernel.org> Sender: keyrings-owner@vger.kernel.org To: keyrings@vger.kernel.org, David Howells Cc: Aaro Koskinen , linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: On Mon, Jan 14, 2019 at 07:37:16PM -0800, Eric Biggers wrote: > From: Eric Biggers > > 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 > 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 > --- > 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 e098cbe27db54..12babe9915944 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; > -- > 2.20.1 > Ping. David, are you planning to apply this? - Eric