From 133800d1f0288b9ddfc0d0aded10d9efa82d5b8c Mon Sep 17 00:00:00 2001 From: Marcelo Ricardo Leitner Date: Tue, 8 Mar 2016 10:34:28 -0300 Subject: sctp: fix copying more bytes than expected in sctp_add_bind_addr Dmitry reported that sctp_add_bind_addr may read more bytes than expected in case the parameter is a IPv4 addr supplied by the user through calls such as sctp_bindx_add(), because it always copies sizeof(union sctp_addr) while the buffer may be just a struct sockaddr_in, which is smaller. This patch then fixes it by limiting the memcpy to the min between the union size and a (new parameter) provided addr size. Where possible this parameter still is the size of that union, except for reading from user-provided buffers, which then it accounts for protocol type. Reported-by: Dmitry Vyukov Tested-by: Dmitry Vyukov Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/bind_addr.c | 14 ++++++++------ net/sctp/protocol.c | 1 + net/sctp/sm_make_chunk.c | 3 ++- net/sctp/socket.c | 4 +++- 4 files changed, 14 insertions(+), 8 deletions(-) (limited to 'net/sctp') diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c index 871cdf9567e6..401c60750b20 100644 --- a/net/sctp/bind_addr.c +++ b/net/sctp/bind_addr.c @@ -111,7 +111,8 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest, dest->port = src->port; list_for_each_entry(addr, &src->address_list, list) { - error = sctp_add_bind_addr(dest, &addr->a, 1, gfp); + error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a), + 1, gfp); if (error < 0) break; } @@ -150,7 +151,7 @@ void sctp_bind_addr_free(struct sctp_bind_addr *bp) /* Add an address to the bind address list in the SCTP_bind_addr structure. */ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new, - __u8 addr_state, gfp_t gfp) + int new_size, __u8 addr_state, gfp_t gfp) { struct sctp_sockaddr_entry *addr; @@ -159,7 +160,7 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new, if (!addr) return -ENOMEM; - memcpy(&addr->a, new, sizeof(*new)); + memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size)); /* Fix up the port if it has not yet been set. * Both v4 and v6 have the port at the same offset. @@ -291,7 +292,8 @@ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, } af->from_addr_param(&addr, rawaddr, htons(port), 0); - retval = sctp_add_bind_addr(bp, &addr, SCTP_ADDR_SRC, gfp); + retval = sctp_add_bind_addr(bp, &addr, sizeof(addr), + SCTP_ADDR_SRC, gfp); if (retval) { /* Can't finish building the list, clean up. */ sctp_bind_addr_clean(bp); @@ -453,8 +455,8 @@ static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest, (((AF_INET6 == addr->sa.sa_family) && (flags & SCTP_ADDR6_ALLOWED) && (flags & SCTP_ADDR6_PEERSUPP)))) - error = sctp_add_bind_addr(dest, addr, SCTP_ADDR_SRC, - gfp); + error = sctp_add_bind_addr(dest, addr, sizeof(*addr), + SCTP_ADDR_SRC, gfp); } return error; diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 1099e99a53c4..d3d50daa248b 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -216,6 +216,7 @@ int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp, (copy_flags & SCTP_ADDR6_ALLOWED) && (copy_flags & SCTP_ADDR6_PEERSUPP)))) { error = sctp_add_bind_addr(bp, &addr->a, + sizeof(addr->a), SCTP_ADDR_SRC, GFP_ATOMIC); if (error) goto end_copy; diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 5d6a03fad378..7fe971e30ad6 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1830,7 +1830,8 @@ no_hmac: /* Also, add the destination address. */ if (list_empty(&retval->base.bind_addr.address_list)) { sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, - SCTP_ADDR_SRC, GFP_ATOMIC); + sizeof(chunk->dest), SCTP_ADDR_SRC, + GFP_ATOMIC); } retval->next_tsn = retval->c.initial_tsn; diff --git a/net/sctp/socket.c b/net/sctp/socket.c index e878da0949db..0e3de0c71137 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -386,7 +386,8 @@ static int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) /* Add the address to the bind address list. * Use GFP_ATOMIC since BHs will be disabled. */ - ret = sctp_add_bind_addr(bp, addr, SCTP_ADDR_SRC, GFP_ATOMIC); + ret = sctp_add_bind_addr(bp, addr, af->sockaddr_len, + SCTP_ADDR_SRC, GFP_ATOMIC); /* Copy back into socket for getsockname() use. */ if (!ret) { @@ -577,6 +578,7 @@ static int sctp_send_asconf_add_ip(struct sock *sk, af = sctp_get_af_specific(addr->v4.sin_family); memcpy(&saveaddr, addr, af->sockaddr_len); retval = sctp_add_bind_addr(bp, &saveaddr, + sizeof(saveaddr), SCTP_ADDR_NEW, GFP_ATOMIC); addr_buf += af->sockaddr_len; } -- cgit v1.2.3