diff options
| author | Gao Feng <gfree.wind@vip.163.com> | 2018-05-30 10:29:31 +0800 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2018-06-01 10:14:51 +0200 |
| commit | 8f4d19aacb64f2b3d65c8cf7974c3d153224b5f2 (patch) | |
| tree | a8d0496a35d5eb92d8517017b8ccea917128fc8a /net/netfilter/xt_CT.c | |
| parent | 664088f8d68178809b848ca450f2797efb34e8e7 (diff) | |
| download | linux-8f4d19aacb64f2b3d65c8cf7974c3d153224b5f2.tar.gz | |
netfilter: xt_CT: Reject the non-null terminated string from user space
The helper and timeout strings are from user-space, we need to make
sure they are null terminated. If not, evil user could make kernel
read the unexpected memory, even print it when fail to find by the
following codes.
pr_info_ratelimited("No such helper \"%s\"\n", helper_name);
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/xt_CT.c')
| -rw-r--r-- | net/netfilter/xt_CT.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c index 8790190c6feb3c..03b9a50ec93bd9 100644 --- a/net/netfilter/xt_CT.c +++ b/net/netfilter/xt_CT.c @@ -245,12 +245,22 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par, } if (info->helper[0]) { + if (strnlen(info->helper, sizeof(info->helper)) == sizeof(info->helper)) { + ret = -ENAMETOOLONG; + goto err3; + } + ret = xt_ct_set_helper(ct, info->helper, par); if (ret < 0) goto err3; } if (info->timeout[0]) { + if (strnlen(info->timeout, sizeof(info->timeout)) == sizeof(info->timeout)) { + ret = -ENAMETOOLONG; + goto err4; + } + ret = xt_ct_set_timeout(ct, par, info->timeout); if (ret < 0) goto err4; |