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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2015-12-14 22:03:39 +0100 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2016-01-05 18:04:00 +0100 |
| commit | 0295617f822f630711f5af03316d3cbda6e737d4 (patch) | |
| tree | e3c39f3fa9134f5891a4384022c1eb51563d8e7e /net/ipv6 | |
| parent | 332c94ea5738e2599dcd0cd3adf1b5278a0c5615 (diff) | |
| download | lwn-0295617f822f630711f5af03316d3cbda6e737d4.tar.gz lwn-0295617f822f630711f5af03316d3cbda6e737d4.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: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/af_inet6.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 98e09df2d769..0747e1406af6 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -115,6 +115,9 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol, !inet_ehash_secret) build_ehash_secret(); + if (protocol < 0 || protocol >= IPPROTO_MAX) + return -EINVAL; + /* Look for the requested type/protocol pair. */ lookup_protocol: err = -ESOCKTNOSUPPORT; |