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 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
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-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From da17c73b6eb74aad3c3c0654394635675b623b3e Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@xxxxxxxxxx>
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@xxxxxxxxxx>
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@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Acked-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/x_tables.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -206,6 +206,9 @@ 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);
@@ -248,6 +251,9 @@ 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@xxxxxxxxxx are
queue-4.4/netfilter-x_tables-avoid-out-of-bounds-reads-in-xt_request_find_-match-target.patch
queue-4.4/netfilter-xt_rateest-acquire-xt_rateest_mutex-for-hash-insert.patch