diff options
author | Neal Cardwell <ncardwell@google.com> | 2012-12-08 19:43:21 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2012-12-09 18:59:37 -0500 |
commit | 1c95df85ca49640576de2f0a850925957b547b84 (patch) | |
tree | f39f7537be01cf536c4f125e0f3671dc83ddc04b | |
parent | ed23ec4f0a510528e0ffe415f9394107418ae854 (diff) | |
download | lwn-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.c | 53 |
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)) |