83 lines
2.5 KiB
Diff
83 lines
2.5 KiB
Diff
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
|
|
Subject: net: add validation for the socket syscall protocol argument
|
|
Date: Mon, 14 Dec 2015 17:17:49 +0100
|
|
Origin: http://article.gmane.org/gmane.linux.network/391482
|
|
|
|
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
|
|
Reported-by: 郭永刚 <guoyonggang@360.cn>
|
|
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
|
|
---
|
|
net/ipv4/af_inet.c | 3 +++
|
|
net/ipv6/af_inet6.c | 3 +++
|
|
net/socket.c | 3 +++
|
|
3 files changed, 9 insertions(+)
|
|
|
|
--- a/net/ipv4/af_inet.c
|
|
+++ b/net/ipv4/af_inet.c
|
|
@@ -261,6 +261,9 @@ static int inet_create(struct net *net,
|
|
int try_loading_module = 0;
|
|
int err;
|
|
|
|
+ if (protocol >= IPPROTO_MAX)
|
|
+ return -EINVAL;
|
|
+
|
|
sock->state = SS_UNCONNECTED;
|
|
|
|
/* Look for the requested type/protocol pair. */
|
|
--- a/net/ipv6/af_inet6.c
|
|
+++ b/net/ipv6/af_inet6.c
|
|
@@ -109,6 +109,9 @@ static int inet6_create(struct net *net,
|
|
int try_loading_module = 0;
|
|
int err;
|
|
|
|
+ if (protocol >= IPPROTO_MAX)
|
|
+ return -EINVAL;
|
|
+
|
|
/* Look for the requested type/protocol pair. */
|
|
lookup_protocol:
|
|
err = -ESOCKTNOSUPPORT;
|
|
--- a/net/socket.c
|
|
+++ b/net/socket.c
|
|
@@ -1105,6 +1105,9 @@ int __sock_create(struct net *net, int f
|
|
return -EAFNOSUPPORT;
|
|
if (type < 0 || type >= SOCK_MAX)
|
|
return -EINVAL;
|
|
+ /* upper bound should be tested by per-protocol .create callbacks */
|
|
+ if (protocol < 0)
|
|
+ return -EINVAL;
|
|
|
|
/* Compatibility.
|
|
|