Commit 133800d1 authored by Marcelo Ricardo Leitner's avatar Marcelo Ricardo Leitner Committed by David S. Miller
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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 <dvyukov@google.com>
Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e2857b8f
...@@ -1098,7 +1098,7 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest, ...@@ -1098,7 +1098,7 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
const struct sctp_bind_addr *src, const struct sctp_bind_addr *src,
gfp_t gfp); gfp_t gfp);
int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, 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_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
struct sctp_sock *); struct sctp_sock *);
......
...@@ -111,7 +111,8 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest, ...@@ -111,7 +111,8 @@ int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
dest->port = src->port; dest->port = src->port;
list_for_each_entry(addr, &src->address_list, list) { 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) if (error < 0)
break; break;
} }
...@@ -150,7 +151,7 @@ void sctp_bind_addr_free(struct sctp_bind_addr *bp) ...@@ -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. */ /* 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, 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; struct sctp_sockaddr_entry *addr;
...@@ -159,7 +160,7 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new, ...@@ -159,7 +160,7 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
if (!addr) if (!addr)
return -ENOMEM; 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. /* Fix up the port if it has not yet been set.
* Both v4 and v6 have the port at the same offset. * 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, ...@@ -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); 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) { if (retval) {
/* Can't finish building the list, clean up. */ /* Can't finish building the list, clean up. */
sctp_bind_addr_clean(bp); sctp_bind_addr_clean(bp);
...@@ -453,8 +455,8 @@ static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest, ...@@ -453,8 +455,8 @@ static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest,
(((AF_INET6 == addr->sa.sa_family) && (((AF_INET6 == addr->sa.sa_family) &&
(flags & SCTP_ADDR6_ALLOWED) && (flags & SCTP_ADDR6_ALLOWED) &&
(flags & SCTP_ADDR6_PEERSUPP)))) (flags & SCTP_ADDR6_PEERSUPP))))
error = sctp_add_bind_addr(dest, addr, SCTP_ADDR_SRC, error = sctp_add_bind_addr(dest, addr, sizeof(*addr),
gfp); SCTP_ADDR_SRC, gfp);
} }
return error; return error;
......
...@@ -216,6 +216,7 @@ int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp, ...@@ -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_ALLOWED) &&
(copy_flags & SCTP_ADDR6_PEERSUPP)))) { (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
error = sctp_add_bind_addr(bp, &addr->a, error = sctp_add_bind_addr(bp, &addr->a,
sizeof(addr->a),
SCTP_ADDR_SRC, GFP_ATOMIC); SCTP_ADDR_SRC, GFP_ATOMIC);
if (error) if (error)
goto end_copy; goto end_copy;
......
...@@ -1830,7 +1830,8 @@ struct sctp_association *sctp_unpack_cookie( ...@@ -1830,7 +1830,8 @@ struct sctp_association *sctp_unpack_cookie(
/* Also, add the destination address. */ /* Also, add the destination address. */
if (list_empty(&retval->base.bind_addr.address_list)) { if (list_empty(&retval->base.bind_addr.address_list)) {
sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 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; 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) ...@@ -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. /* Add the address to the bind address list.
* Use GFP_ATOMIC since BHs will be disabled. * 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. */ /* Copy back into socket for getsockname() use. */
if (!ret) { if (!ret) {
...@@ -577,6 +578,7 @@ static int sctp_send_asconf_add_ip(struct sock *sk, ...@@ -577,6 +578,7 @@ static int sctp_send_asconf_add_ip(struct sock *sk,
af = sctp_get_af_specific(addr->v4.sin_family); af = sctp_get_af_specific(addr->v4.sin_family);
memcpy(&saveaddr, addr, af->sockaddr_len); memcpy(&saveaddr, addr, af->sockaddr_len);
retval = sctp_add_bind_addr(bp, &saveaddr, retval = sctp_add_bind_addr(bp, &saveaddr,
sizeof(saveaddr),
SCTP_ADDR_NEW, GFP_ATOMIC); SCTP_ADDR_NEW, GFP_ATOMIC);
addr_buf += af->sockaddr_len; addr_buf += af->sockaddr_len;
} }
......
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