| Date | Mon, 25 Apr 2011 22:04:52 +0200 | From | Willy Tarreau <> | Subject | [PATCH 140/173] netfilter: ipt_CLUSTERIP: fix buffer overflow |
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2.6.27.59-stable review patch. If anyone has any objections, please let us know.
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From: Vasiliy Kulikov <segoon@openwall.com>
commit 961ed183a9fd080cf306c659b8736007e44065a5 upstream.
'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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- net/ipv4/netfilter/ipt_CLUSTERIP.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -666,8 +666,11 @@ static ssize_t clusterip_proc_write(stru struct clusterip_config *c = pde->data; 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);
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