| From da17c73b6eb74aad3c3c0654394635675b623b3e Mon Sep 17 00:00:00 2001 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Wed, 24 Jan 2018 17:16:09 -0800 |
| Subject: netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_{match|target} |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| commit da17c73b6eb74aad3c3c0654394635675b623b3e upstream. |
| |
| It looks like syzbot found its way into netfilter territory. |
| |
| Issue here is that @name comes from user space and might |
| not be null terminated. |
| |
| Out-of-bound reads happen, KASAN is not happy. |
| |
| v2 added similar fix for xt_request_find_target(), |
| as Florian advised. |
| |
| Signed-off-by: Eric Dumazet <edumazet@google.com> |
| Reported-by: syzbot <syzkaller@googlegroups.com> |
| Acked-by: Florian Westphal <fw@strlen.de> |
| Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| net/netfilter/x_tables.c | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| --- a/net/netfilter/x_tables.c |
| +++ b/net/netfilter/x_tables.c |
| @@ -209,6 +209,9 @@ xt_request_find_match(uint8_t nfproto, c |
| { |
| struct xt_match *match; |
| |
| + if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
| + return ERR_PTR(-EINVAL); |
| + |
| match = xt_find_match(nfproto, name, revision); |
| if (IS_ERR(match)) { |
| request_module("%st_%s", xt_prefix[nfproto], name); |
| @@ -251,6 +254,9 @@ struct xt_target *xt_request_find_target |
| { |
| struct xt_target *target; |
| |
| + if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN) |
| + return ERR_PTR(-EINVAL); |
| + |
| target = xt_find_target(af, name, revision); |
| if (IS_ERR(target)) { |
| request_module("%st_%s", xt_prefix[af], name); |