Vlad Yasevich wrote:
> The structure used for SCTP_AUTH_KEY option contains a
> length that needs to be verfied to prevent buffer overflow
> conditions. Spoted by Eugene Teo <eteo@xxxxxxxxxx>.
>
> Signed-off-by: Vlad Yasevich <vladislav.yasevich@xxxxxx>
> ---
> net/sctp/auth.c | 4 ++++
> net/sctp/socket.c | 5 +++++
> 2 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/net/sctp/auth.c b/net/sctp/auth.c
> index 675a5c3..1fcb4cf 100644
> --- a/net/sctp/auth.c
> +++ b/net/sctp/auth.c
> @@ -80,6 +80,10 @@ static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
This should be __u16 key_len.
> {
> struct sctp_auth_bytes *key;
>
> + /* Verify that we are not going to overflow INT_MAX */
> + if ((INT_MAX - key_len) < sizeof(struct sctp_auth_bytes))
> + return NULL;
Shouldn't this be UINT_MAX? But then if you are going to change
sctp_auth_create_key() to accept __u16 key_len, then it should be
USHORT_MAX.
> /* Allocate the shared key */
> key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
> if (!key)
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index bb5c9ef..afa952e 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -3144,6 +3144,11 @@ static int sctp_setsockopt_auth_key(struct sock *sk,
> goto out;
> }
>
> + if (authkey->sca_keylength > optlen) {
> + ret = -EINVAL;
> + goto out;
Is there a better upper bound check?
> asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
> if (!asoc && authkey->sca_assoc_id && sctp_style(sk, UDP)) {
> ret = -EINVAL;
Thanks,
Eugene
--
To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
