netdev - [PATCH net] ipv6: fix the check before getting the cookie in rt6_get

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <49388c263f652f91bad8a0d3687df7bb4a18f0da.1559473846.git.lucien.xin@gmail.com>
Date:   Sun,  2 Jun 2019 19:10:46 +0800
From:   Xin Long <lucien.xin@...il.com>
To:     network dev <netdev@...r.kernel.org>
Cc:     davem@...emloft.net, David Ahern <dsahern@...il.com>
Subject: [PATCH net] ipv6: fix the check before getting the cookie in rt6_get_cookie

In Jianlin's testing, netperf was broken with 'Connection reset by peer',
as the cookie check failed in rt6_check() and ip6_dst_check() always
returned NULL.

It's caused by Commit 93531c674315 ("net/ipv6: separate handling of FIB
entries from dst based routes"), where the cookie can be got only when
'c1'(see below) for setting dst_cookie whereas rt6_check() is called
when !'c1' for checking dst_cookie, as we can see in ip6_dst_check().

Since in ip6_dst_check() both rt6_dst_from_check() (c1) and rt6_check()
(!c1) will check the 'from' cookie, this patch is to remove the c1 check
in rt6_get_cookie(), so that the dst_cookie can always be set properly.

c1:
  (rt->rt6i_flags & RTF_PCPU || unlikely(!list_empty(&rt->rt6i_uncached)))

Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: Jianlin Shi <jishi@...hat.com>
Signed-off-by: Xin Long <lucien.xin@...il.com>
---
 include/net/ip6_fib.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 525f701..d6d936c 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -263,8 +263,7 @@ static inline u32 rt6_get_cookie(const struct rt6_info *rt)
 	rcu_read_lock();

 	from = rcu_dereference(rt->from);
-	if (from && (rt->rt6i_flags & RTF_PCPU ||
-	    unlikely(!list_empty(&rt->rt6i_uncached))))
+	if (from)
 		fib6_get_cookie_safe(from, &cookie);

 	rcu_read_unlock();
-- 
2.1.0