| From | Herton Ronaldo Krzesinski <> | Subject | [PATCH 147/222] inet_diag: fix oops for IPv4 AF_INET6 TCP SYN-RECV state | Date | Wed, 16 Jan 2013 13:55:47 -0200 |
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3.5.7.3 -stable review patch. If anyone has any objections, please let me know.
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From: Neal Cardwell <ncardwell@google.com>
commit 1c95df85ca49640576de2f0a850925957b547b84 upstream.
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> [ herton: adjust context ] Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- net/ipv4/inet_diag.c | 53 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 14 deletions(-)
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 1bfc104..d780fca 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 }; #define INET_DIAG_PUT(skb, attrtype, attrlen) \ @@ -586,6 +590,36 @@ 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, u32 pid, u32 seq, const struct nlmsghdr *unlh) @@ -624,8 +658,10 @@ 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 nlh->nlmsg_len = skb_tail_pointer(skb) - b; @@ -683,18 +719,7 @@ 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)) -- 1.7.9.5
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