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authorHannes Frederic Sowa <hannes@stressinduktion.org>2015-12-14 22:03:39 +0100
committerDavid S. Miller <davem@davemloft.net>2015-12-14 16:09:30 -0500
commit79462ad02e861803b3840cc782248c7359451cd9 (patch)
treedd000edadb23174c68e34fc3929d6368b2bd9c37
parent20b08e1a793d898f0f13040d5418ee0955f678cf (diff)
net: add validation for the socket syscall protocol argument
郭永刚 reported that one could simply crash the kernel as root by using a simple program: int socket_fd; struct sockaddr_in addr; addr.sin_port = 0; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_family = 10; socket_fd = socket(10,3,0x40000000); connect(socket_fd , &addr,16); AF_INET, AF_INET6 sockets actually only support 8-bit protocol identifiers. inet_sock's skc_protocol field thus is sized accordingly, thus larger protocol identifiers simply cut off the higher bits and store a zero in the protocol fields. This could lead to e.g. NULL function pointer because as a result of the cut off inet_num is zero and we call down to inet_autobind, which is NULL for raw sockets. kernel: Call Trace: kernel: [<ffffffff816db90e>] ? inet_autobind+0x2e/0x70 kernel: [<ffffffff816db9a4>] inet_dgram_connect+0x54/0x80 kernel: [<ffffffff81645069>] SYSC_connect+0xd9/0x110 kernel: [<ffffffff810ac51b>] ? ptrace_notify+0x5b/0x80 kernel: [<ffffffff810236d8>] ? syscall_trace_enter_phase2+0x108/0x200 kernel: [<ffffffff81645e0e>] SyS_connect+0xe/0x10 kernel: [<ffffffff81779515>] tracesys_phase2+0x84/0x89 I found no particular commit which introduced this problem. CVE: CVE-2015-8543 Cc: Cong Wang <cwang@twopensource.com> Reported-by: 郭永刚 <guoyonggang@360.cn> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/sock.h1
-rw-r--r--net/ax25/af_ax25.c3
-rw-r--r--net/decnet/af_decnet.c3
-rw-r--r--net/ipv4/af_inet.c3
-rw-r--r--net/ipv6/af_inet6.c3
-rw-r--r--net/irda/af_irda.c3
6 files changed, 16 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index eaef41433d7a..c4205e0a3a2d 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -403,6 +403,7 @@ struct sock {
sk_no_check_rx : 1,
sk_userlocks : 4,
sk_protocol : 8,
+#define SK_PROTOCOL_MAX U8_MAX
sk_type : 16;
kmemcheck_bitfield_end(flags);
int sk_wmem_queued;
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index ae3a47f9d1d5..fbd0acf80b13 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -805,6 +805,9 @@ static int ax25_create(struct net *net, struct socket *sock, int protocol,
struct sock *sk;
ax25_cb *ax25;
+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
+ return -EINVAL;
+
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index eebf5ac8ce18..13d6b1a6e0fc 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -678,6 +678,9 @@ static int dn_create(struct net *net, struct socket *sock, int protocol,
{
struct sock *sk;
+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
+ return -EINVAL;
+
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 11c4ca13ec3b..5c5db6636704 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -257,6 +257,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
int try_loading_module = 0;
int err;
+ if (protocol < 0 || protocol >= IPPROTO_MAX)
+ return -EINVAL;
+
sock->state = SS_UNCONNECTED;
/* Look for the requested type/protocol pair. */
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 8ec0df75f1c4..9f5137cd604e 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -109,6 +109,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
int try_loading_module = 0;
int err;
+ if (protocol < 0 || protocol >= IPPROTO_MAX)
+ return -EINVAL;
+
/* Look for the requested type/protocol pair. */
lookup_protocol:
err = -ESOCKTNOSUPPORT;
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index e6aa48b5395c..923abd6b3064 100644
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1086,6 +1086,9 @@ static int irda_create(struct net *net, struct socket *sock, int protocol,
struct sock *sk;
struct irda_sock *self;
+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
+ return -EINVAL;
+
if (net != &init_net)
return -EAFNOSUPPORT;