From: Eric Biggers <[email protected]>
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 <[email protected]>
Fixes: 2aa349f6e37c ("[PATCH] Keys: Export user-defined keyring operations")
Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities")
Cc: [email protected]
Signed-off-by: Eric Biggers <[email protected]>
---
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
Hi,
On Mon, Jan 14, 2019 at 07:37:16PM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> 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 <[email protected]>
> Fixes: 2aa349f6e37c ("[PATCH] Keys: Export user-defined keyring operations")
> Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities")
> Cc: [email protected]
> Signed-off-by: Eric Biggers <[email protected]>
Tested-by: Aaro Koskinen <[email protected]>
This fixes the "unaligned access" dmesg spam on SPARC when using ext4
encryption.
Thanks,
A.
> ---
> 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
>
On Mon, Jan 14, 2019 at 07:37:16PM -0800, Eric Biggers wrote:
> From: Eric Biggers <[email protected]>
>
> 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 <[email protected]>
> Fixes: 2aa349f6e37c ("[PATCH] Keys: Export user-defined keyring operations")
> Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities")
> Cc: [email protected]
> Signed-off-by: Eric Biggers <[email protected]>
> ---
> 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
On Thu, Feb 07, 2019 at 03:35:09PM -0800, Eric Biggers wrote:
> On Mon, Jan 14, 2019 at 07:37:16PM -0800, Eric Biggers wrote:
> > From: Eric Biggers <[email protected]>
> >
> > 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 <[email protected]>
> > Fixes: 2aa349f6e37c ("[PATCH] Keys: Export user-defined keyring operations")
> > Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities")
> > Cc: [email protected]
> > Signed-off-by: Eric Biggers <[email protected]>
> > ---
> > 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
Ping.