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authorHannes Frederic Sowa <hannes@stressinduktion.org>2015-12-14 22:03:39 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-01-22 20:54:13 -0800
commitbc8f79b522b57ca79a676615003d85b08162ff5a (patch)
treea264de7defccc12b08dcc6a0503614d5f33e21cb /net/ipv6
parent683f40ec958e669b0d376a0d83c0213783ee7f99 (diff)
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/af_inet6.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 2d044d2a2ccf..bad62fa5e70f 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;