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authorHannes Frederic Sowa <hannes@stressinduktion.org>2015-12-14 22:03:39 +0100
committerSasha Levin <sasha.levin@oracle.com>2016-01-15 18:41:51 -0500
commite60ccfd9e596b48d4b9d6e2b5440261c83d10c12 (patch)
treee28a5fdd5d0d6382d7ef163bff97bde230410762
parentd6d2547876dd3c44d1359c522d2943f05b2d44bf (diff)
downloadlwn-e60ccfd9e596b48d4b9d6e2b5440261c83d10c12.tar.gz
lwn-e60ccfd9e596b48d4b9d6e2b5440261c83d10c12.zip
net: add validation for the socket syscall protocol argument
[ Upstream commit 79462ad02e861803b3840cc782248c7359451cd9 ] 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> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-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 bc50326f0532..2b12e04447eb 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -379,6 +379,7 @@ 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 c35c3f48fc0f..1428c3ff3341 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -806,6 +806,9 @@ 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 25733d538147..2aeeb4f22e9d 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 9a173577a790..6cf020ea4f46 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -259,6 +259,9 @@ 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 05417c330f4e..ad95905e7a70 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 3f3a6cbdceb7..b3f6ec0df426 100644
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1100,6 +1100,9 @@ static int irda_create(struct net *net, struct socket *sock, int protocol,
IRDA_DEBUG(2, "%s()\n", __func__);
+ if (protocol < 0 || protocol > SK_PROTOCOL_MAX)
+ return -EINVAL;
+
if (net != &init_net)
return -EAFNOSUPPORT;