Commit 133800d1 authored by Marcelo Ricardo Leitner's avatar Marcelo Ricardo Leitner Committed by David S. Miller
Browse files

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: default avatarDmitry Vyukov <>
Tested-by: default avatarDmitry Vyukov <>
Signed-off-by: default avatarMarcelo Ricardo Leitner <>
Signed-off-by: default avatarDavid S. Miller <>
parent e2857b8f
......@@ -1098,7 +1098,7 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
const struct sctp_bind_addr *src,
gfp_t gfp);
int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
__u8 addr_state, gfp_t gfp);
int new_size, __u8 addr_state, gfp_t gfp);
int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
struct sctp_sock *);
......@@ -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)
......@@ -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),
if (retval) {
/* Can't finish building the list, clean up. */
......@@ -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,
error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
return error;
......@@ -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,
if (error)
goto end_copy;
......@@ -1830,7 +1830,8 @@ struct sctp_association *sctp_unpack_cookie(
/* Also, add the destination address. */
if (list_empty(&retval->base.bind_addr.address_list)) {
sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
sizeof(chunk->dest), SCTP_ADDR_SRC,
retval->next_tsn = retval->c.initial_tsn;
......@@ -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,
/* 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,
addr_buf += af->sockaddr_len;
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