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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>
This commit is contained in:
Neal Cardwell 2012-12-08 19:43:21 +00:00 committed by David S. Miller
parent ed23ec4f0a
commit 1c95df85ca
1 changed files with 39 additions and 14 deletions
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53
net/ipv4/inet_diag.c
View File

@ -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))