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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2015-12-14 22:03:39 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-12-30 02:26:03 +0000 |
| commit | ef6d51d24d878be2291d7af783441356eb77649d (patch) | |
| tree | 5954130bfa872b0ceaa7d763fbbe14a421c8dd92 /net/ax25/af_ax25.c | |
| parent | 5c85649e8da22945f8e4616717543991a81bfba2 (diff) | |
| download | linux-stable-ef6d51d24d878be2291d7af783441356eb77649d.tar.gz linux-stable-ef6d51d24d878be2291d7af783441356eb77649d.tar.bz2 linux-stable-ef6d51d24d878be2291d7af783441356eb77649d.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>
[bwh: Backported to 3.2: open-code U8_MAX]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/ax25/af_ax25.c')
| -rw-r--r-- | net/ax25/af_ax25.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 7b8db0ede163..a314cfd6a642 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; |