This is a note to let you know that I've just added the patch titled

netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_{match|target}

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: netfilter-x_tables-avoid-out-of-bounds-reads-in-xt_request_find_-match-target.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

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 @@ -207,6 +207,9 @@ 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); @@ -249,6 +252,9 @@ 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);

Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.9/kcm-check-if-sk_user_data-already-set-in-kcm_attach.patch queue-4.9/netfilter-x_tables-avoid-out-of-bounds-reads-in-xt_request_find_-match-target.patch queue-4.9/kcm-only-allow-tcp-sockets-to-be-attached-to-a-kcm-mux.patch queue-4.9/netfilter-xt_rateest-acquire-xt_rateest_mutex-for-hash-insert.patch