From c76f97c99ae6d26d14c7f0e50e074382bfbc9f98 Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Mon, 8 Jan 2018 19:02:29 -0200 Subject: [PATCH] sctp: make use of pre-calculated len Some sockopt handling functions were calculating the length of the buffer to be written to userspace and then calculating it again when actually writing the buffer, which could lead to some write not using an up-to-date length. This patch updates such places to just make use of the len variable. Also, replace some sizeof(type) to sizeof(var). Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 022b94f..9b01e99 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -5025,7 +5025,7 @@ static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optv len = sizeof(int); if (put_user(len, optlen)) return -EFAULT; - if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int))) + if (copy_to_user(optval, &sctp_sk(sk)->autoclose, len)) return -EFAULT; return 0; } @@ -5655,6 +5655,9 @@ copy_getaddrs: err = -EFAULT; goto out; } + /* XXX: We should have accounted for sizeof(struct sctp_getaddrs) too, + * but we can't change it anymore. + */ if (put_user(bytes_copied, optlen)) err = -EFAULT; out: @@ -6091,7 +6094,7 @@ static int sctp_getsockopt_maxseg(struct sock *sk, int len, params.assoc_id = 0; } else if (len >= sizeof(struct sctp_assoc_value)) { len = sizeof(struct sctp_assoc_value); - if (copy_from_user(¶ms, optval, sizeof(params))) + if (copy_from_user(¶ms, optval, len)) return -EFAULT; } else return -EINVAL; @@ -6261,7 +6264,9 @@ static int sctp_getsockopt_active_key(struct sock *sk, int len, if (len < sizeof(struct sctp_authkeyid)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authkeyid))) + + len = sizeof(struct sctp_authkeyid); + if (copy_from_user(&val, optval, len)) return -EFAULT; asoc = sctp_id2assoc(sk, val.scact_assoc_id); @@ -6273,7 +6278,6 @@ static int sctp_getsockopt_active_key(struct sock *sk, int len, else val.scact_keynumber = ep->active_key_id; - len = sizeof(struct sctp_authkeyid); if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, &val, len)) @@ -6299,7 +6303,7 @@ static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len, if (len < sizeof(struct sctp_authchunks)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks))) + if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; to = p->gauth_chunks; @@ -6344,7 +6348,7 @@ static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len, if (len < sizeof(struct sctp_authchunks)) return -EINVAL; - if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks))) + if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT; to = p->gauth_chunks; -- 2.7.4