Use the kernel pointer that sctp_setsockopt has available instead of directly handling the user pointer.
Signed-off-by: Christoph Hellwig <[email protected]> --- net/sctp/socket.c | 38 ++++++++++++-------------------------- 1 file changed, 12 insertions(+), 26 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index ee6a618ee3e8e..eb08e44c0c57a 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -972,42 +972,33 @@ int sctp_asconf_mgmt(struct sctp_sock *sp, struct sctp_sockaddr_entry *addrw) * 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 * op Operation to perform (add or remove, see the flags of * sctp_bindx) * * Returns 0 if ok, <0 errno code on error. */ -static int sctp_setsockopt_bindx(struct sock *sk, - struct sockaddr __user *addrs, - int addrs_size, int op) +static int sctp_setsockopt_bindx(struct sock *sk, void *addr_buf, + int addrs_size, int op) { - struct sockaddr *kaddrs; + struct sockaddr *kaddrs = addr_buf; int err; int addrcnt = 0; int walk_size = 0; struct sockaddr *sa_addr; - void *addr_buf; struct sctp_af *af; pr_debug("%s: sk:%p addrs:%p addrs_size:%d opt:%d\n", - __func__, sk, addrs, addrs_size, op); + __func__, sk, addr_buf, addrs_size, op); if (unlikely(addrs_size <= 0)) return -EINVAL; - kaddrs = memdup_user(addrs, addrs_size); - if (IS_ERR(kaddrs)) - return PTR_ERR(kaddrs); - /* Walk through the addrs buffer and count the number of addresses. */ - addr_buf = kaddrs; while (walk_size < addrs_size) { - if (walk_size + sizeof(sa_family_t) > addrs_size) { - kfree(kaddrs); + if (walk_size + sizeof(sa_family_t) > addrs_size) return -EINVAL; - } sa_addr = addr_buf; af = sctp_get_af_specific(sa_addr->sa_family); @@ -1015,10 +1006,8 @@ static int sctp_setsockopt_bindx(struct sock *sk, /* If the address family is not supported or if this address * causes the address buffer to overflow return EINVAL. */ - if (!af || (walk_size + af->sockaddr_len) > addrs_size) { - kfree(kaddrs); + if (!af || (walk_size + af->sockaddr_len) > addrs_size) return -EINVAL; - } addrcnt++; addr_buf += af->sockaddr_len; walk_size += af->sockaddr_len; @@ -1029,8 +1018,7 @@ static int sctp_setsockopt_bindx(struct sock *sk, case SCTP_BINDX_ADD_ADDR: /* Allow security module to validate bindx addresses. */ err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD, - (struct sockaddr *)kaddrs, - addrs_size); + kaddrs, addrs_size); if (err) goto out; err = sctp_bindx_add(sk, kaddrs, addrcnt); @@ -1052,8 +1040,6 @@ static int sctp_setsockopt_bindx(struct sock *sk, } out: - kfree(kaddrs); - return err; } @@ -4698,14 +4684,14 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, switch (optname) { case SCTP_SOCKOPT_BINDX_ADD: /* 'optlen' is the size of the addresses buffer. */ - retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval, - optlen, SCTP_BINDX_ADD_ADDR); + retval = sctp_setsockopt_bindx(sk, kopt, optlen, + SCTP_BINDX_ADD_ADDR); break; case SCTP_SOCKOPT_BINDX_REM: /* 'optlen' is the size of the addresses buffer. */ - retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval, - optlen, SCTP_BINDX_REM_ADDR); + retval = sctp_setsockopt_bindx(sk, kopt, optlen, + SCTP_BINDX_REM_ADDR); break; case SCTP_SOCKOPT_CONNECTX_OLD: -- 2.26.2
