diff options
| author | Vasiliy Kulikov <segoon@openwall.com> | 2011-03-20 15:42:52 +0100 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2011-03-20 15:42:52 +0100 |
| commit | 961ed183a9fd080cf306c659b8736007e44065a5 (patch) | |
| tree | 7bf0a65c184a2c4fc0571ff9af8ce633efc73bcf /net | |
| parent | db856674ac69e31946e56085239757cca3f7655f (diff) | |
| download | lwn-961ed183a9fd080cf306c659b8736007e44065a5.tar.gz lwn-961ed183a9fd080cf306c659b8736007e44065a5.zip | |
netfilter: ipt_CLUSTERIP: fix buffer overflow
'buffer' string is copied from userspace. It is not checked whether it is
zero terminated. This may lead to overflow inside of simple_strtoul().
Changli Gao suggested to copy not more than user supplied 'size' bytes.
It was introduced before the git epoch. Files "ipt_CLUSTERIP/*" are
root writable only by default, however, on some setups permissions might be
relaxed to e.g. network admin user.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/netfilter/ipt_CLUSTERIP.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 403ca57f6011..d609ac3cb9a4 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -664,8 +664,11 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, char buffer[PROC_WRITELEN+1]; unsigned long nodenum; - if (copy_from_user(buffer, input, PROC_WRITELEN)) + if (size > PROC_WRITELEN) + return -EIO; + if (copy_from_user(buffer, input, size)) return -EFAULT; + buffer[size] = 0; if (*buffer == '+') { nodenum = simple_strtoul(buffer+1, NULL, 10); |