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authorNeal Cardwell <ncardwell@google.com>2012-12-08 19:43:21 +0000
committerDavid S. Miller <davem@davemloft.net>2012-12-09 18:59:37 -0500
commit1c95df85ca49640576de2f0a850925957b547b84 (patch)
treef39f7537be01cf536c4f125e0f3671dc83ddc04b
parented23ec4f0a510528e0ffe415f9394107418ae854 (diff)
downloadlwn-1c95df85ca49640576de2f0a850925957b547b84.tar.gz
lwn-1c95df85ca49640576de2f0a850925957b547b84.zip
inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state
Fix inet_diag to be aware of the fact that AF_INET6 TCP connections instantiated for IPv4 traffic and in the SYN-RECV state were actually created with inet_reqsk_alloc(), instead of inet6_reqsk_alloc(). This means that for such connections inet6_rsk(req) returns a pointer to a random spot in memory up to roughly 64KB beyond the end of the request_sock. With this bug, for a server using AF_INET6 TCP sockets and serving IPv4 traffic, an inet_diag user like `ss state SYN-RECV` would lead to inet_diag_fill_req() causing an oops or the export to user space of 16 bytes of kernel memory as a garbage IPv6 address, depending on where the garbage inet6_rsk(req) pointed. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/inet_diag.c53
1 files changed, 39 insertions, 14 deletions
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 0c34bfabc11f..16cfa42cfd99 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -44,6 +44,10 @@ struct inet_diag_entry {
u16 dport;
u16 family;
u16 userlocks;
+#if IS_ENABLED(CONFIG_IPV6)
+ struct in6_addr saddr_storage; /* for IPv4-mapped-IPv6 addresses */
+ struct in6_addr daddr_storage; /* for IPv4-mapped-IPv6 addresses */
+#endif
};
static DEFINE_MUTEX(inet_diag_table_mutex);
@@ -596,6 +600,36 @@ static int inet_twsk_diag_dump(struct inet_timewait_sock *tw,
cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
}
+/* Get the IPv4, IPv6, or IPv4-mapped-IPv6 local and remote addresses
+ * from a request_sock. For IPv4-mapped-IPv6 we must map IPv4 to IPv6.
+ */
+static inline void inet_diag_req_addrs(const struct sock *sk,
+ const struct request_sock *req,
+ struct inet_diag_entry *entry)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+#if IS_ENABLED(CONFIG_IPV6)
+ if (sk->sk_family == AF_INET6) {
+ if (req->rsk_ops->family == AF_INET6) {
+ entry->saddr = inet6_rsk(req)->loc_addr.s6_addr32;
+ entry->daddr = inet6_rsk(req)->rmt_addr.s6_addr32;
+ } else if (req->rsk_ops->family == AF_INET) {
+ ipv6_addr_set_v4mapped(ireq->loc_addr,
+ &entry->saddr_storage);
+ ipv6_addr_set_v4mapped(ireq->rmt_addr,
+ &entry->daddr_storage);
+ entry->saddr = entry->saddr_storage.s6_addr32;
+ entry->daddr = entry->daddr_storage.s6_addr32;
+ }
+ } else
+#endif
+ {
+ entry->saddr = &ireq->loc_addr;
+ entry->daddr = &ireq->rmt_addr;
+ }
+}
+
static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
struct request_sock *req,
struct user_namespace *user_ns,
@@ -637,8 +671,10 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
r->idiag_inode = 0;
#if IS_ENABLED(CONFIG_IPV6)
if (r->idiag_family == AF_INET6) {
- *(struct in6_addr *)r->id.idiag_src = inet6_rsk(req)->loc_addr;
- *(struct in6_addr *)r->id.idiag_dst = inet6_rsk(req)->rmt_addr;
+ struct inet_diag_entry entry;
+ inet_diag_req_addrs(sk, req, &entry);
+ memcpy(r->id.idiag_src, entry.saddr, sizeof(struct in6_addr));
+ memcpy(r->id.idiag_dst, entry.daddr, sizeof(struct in6_addr));
}
#endif
@@ -691,18 +727,7 @@ static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk,
continue;
if (bc) {
- entry.saddr =
-#if IS_ENABLED(CONFIG_IPV6)
- (entry.family == AF_INET6) ?
- inet6_rsk(req)->loc_addr.s6_addr32 :
-#endif
- &ireq->loc_addr;
- entry.daddr =
-#if IS_ENABLED(CONFIG_IPV6)
- (entry.family == AF_INET6) ?
- inet6_rsk(req)->rmt_addr.s6_addr32 :
-#endif
- &ireq->rmt_addr;
+ inet_diag_req_addrs(sk, req, &entry);
entry.dport = ntohs(ireq->rmt_port);
if (!inet_diag_bc_run(bc, &entry))