| Submitter | Andy Whitcroft |
|---|---|
| Date | July 7, 2011, 9:28 a.m. |
| Message ID | <1310030885-17977-2-git-send-email-apw@canonical.com> |
| Download | mbox | patch |
| Permalink | /patch/103625/ |
| State | New |
| Headers | show |
Comments
On 07.07.2011 11:28, Andy Whitcroft wrote: > From: Vasiliy Kulikov <segoon@openwall.com> > > '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> > > (cherry picked from commit 961ed183a9fd080cf306c659b8736007e44065a5) > CVE-2011-2534 > BugLink: http://bugs.launchpad.net/bugs/801473 > Signed-off-by: Andy Whitcroft <apw@canonical.com> > --- > 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 2f544da..6420953 100644 > --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c > +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c > @@ -686,8 +686,11 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, > 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); Looks reasonable. Acked-by: Stefan Bader <stefan.bader@canonical.com>
Patch
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 2f544da..6420953 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -686,8 +686,11 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input, 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);