From ce5b2f8929df3ecac3cea44371637241ba816827 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 19 Jul 2020 09:21:40 +0200 Subject: [PATCH] sctp: pass a kernel pointer to __sctp_setsockopt_connectx Use the kernel pointer that sctp_setsockopt has available instead of directly handling the user pointer. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller --- net/sctp/socket.c | 50 +++++++++++++++++++------------------------------- 1 file changed, 19 insertions(+), 31 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 85ba515..44cf284 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1286,36 +1286,29 @@ out_free: * it. * * sk The sk of the socket - * addrs The pointer to the addresses in user land + * addrs The pointer to the addresses * addrssize Size of the addrs buffer * * Returns >=0 if ok, <0 errno code on error. */ -static int __sctp_setsockopt_connectx(struct sock *sk, - struct sockaddr __user *addrs, - int addrs_size, - sctp_assoc_t *assoc_id) +static int __sctp_setsockopt_connectx(struct sock *sk, struct sockaddr *kaddrs, + int addrs_size, sctp_assoc_t *assoc_id) { - struct sockaddr *kaddrs; int err = 0, flags = 0; pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n", - __func__, sk, addrs, addrs_size); + __func__, sk, kaddrs, addrs_size); /* make sure the 1st addr's sa_family is accessible later */ if (unlikely(addrs_size < sizeof(sa_family_t))) return -EINVAL; - kaddrs = memdup_user(addrs, addrs_size); - if (IS_ERR(kaddrs)) - return PTR_ERR(kaddrs); - /* Allow security module to validate connectx addresses. */ err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_CONNECTX, (struct sockaddr *)kaddrs, addrs_size); if (err) - goto out_free; + return err; /* in-kernel sockets don't generally have a file allocated to them * if all they do is call sock_create_kern(). @@ -1323,12 +1316,7 @@ static int __sctp_setsockopt_connectx(struct sock *sk, if (sk->sk_socket->file) flags = sk->sk_socket->file->f_flags; - err = __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id); - -out_free: - kfree(kaddrs); - - return err; + return __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id); } /* @@ -1336,10 +1324,10 @@ out_free: * to the option that doesn't provide association id. */ static int sctp_setsockopt_connectx_old(struct sock *sk, - struct sockaddr __user *addrs, + struct sockaddr *kaddrs, int addrs_size) { - return __sctp_setsockopt_connectx(sk, addrs, addrs_size, NULL); + return __sctp_setsockopt_connectx(sk, kaddrs, addrs_size, NULL); } /* @@ -1349,13 +1337,13 @@ static int sctp_setsockopt_connectx_old(struct sock *sk, * always positive. */ static int sctp_setsockopt_connectx(struct sock *sk, - struct sockaddr __user *addrs, + struct sockaddr *kaddrs, int addrs_size) { sctp_assoc_t assoc_id = 0; int err = 0; - err = __sctp_setsockopt_connectx(sk, addrs, addrs_size, &assoc_id); + err = __sctp_setsockopt_connectx(sk, kaddrs, addrs_size, &assoc_id); if (err) return err; @@ -1385,6 +1373,7 @@ static int sctp_getsockopt_connectx3(struct sock *sk, int len, { struct sctp_getaddrs_old param; sctp_assoc_t assoc_id = 0; + struct sockaddr *kaddrs; int err = 0; #ifdef CONFIG_COMPAT @@ -1408,9 +1397,12 @@ static int sctp_getsockopt_connectx3(struct sock *sk, int len, return -EFAULT; } - err = __sctp_setsockopt_connectx(sk, (struct sockaddr __user *) - param.addrs, param.addr_num, - &assoc_id); + kaddrs = memdup_user(param.addrs, param.addr_num); + if (IS_ERR(kaddrs)) + return PTR_ERR(kaddrs); + + err = __sctp_setsockopt_connectx(sk, kaddrs, param.addr_num, &assoc_id); + kfree(kaddrs); if (err == 0 || err == -EINPROGRESS) { if (copy_to_user(optval, &assoc_id, sizeof(assoc_id))) return -EFAULT; @@ -4700,16 +4692,12 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, case SCTP_SOCKOPT_CONNECTX_OLD: /* 'optlen' is the size of the addresses buffer. */ - retval = sctp_setsockopt_connectx_old(sk, - (struct sockaddr __user *)optval, - optlen); + retval = sctp_setsockopt_connectx_old(sk, kopt, optlen); break; case SCTP_SOCKOPT_CONNECTX: /* 'optlen' is the size of the addresses buffer. */ - retval = sctp_setsockopt_connectx(sk, - (struct sockaddr __user *)optval, - optlen); + retval = sctp_setsockopt_connectx(sk, kopt, optlen); break; case SCTP_DISABLE_FRAGMENTS: -- 2.7.4