linux-kernel - Re: net/dccp: dccp_create_openreq

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

Date:   Wed, 1 Mar 2017 12:35:10 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Dmitry Vyukov <dvyukov@...gle.com>
Cc:     Gerrit Renker <gerrit@....abdn.ac.uk>,
        David Miller <davem@...emloft.net>, dccp@...r.kernel.org,
        netdev <netdev@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Cong Wang <xiyou.wangcong@...il.com>,
        syzkaller <syzkaller@...glegroups.com>
Subject: Re: net/dccp: dccp_create_openreq_child freed held lock

Em Wed, Mar 01, 2017 at 10:38:54AM +0100, Dmitry Vyukov escreveu:
> Hello,
> 
> I've got the following report while running syzkaller fuzzer on
> 86292b33d4b79ee03e2f43ea0381ef85f077c760:
> 
> 
> It seems that dccp_create_openreq_child needs to unlock the sock if
> dccp_feat_activate_values fails.

Yeah, can you please use the patch below, that mimics the error paths in
sk_clone_new(), from where I think even the comment about it being a raw
copy came, but the bh_unlock_sock() didn't?

- Arnaldo

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 53eddf99e4f6..d20d948a98ed 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -122,6 +122,7 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
 			/* It is still raw copy of parent, so invalidate
 			 * destructor and make plain sk_free() */
 			newsk->sk_destruct = NULL;
+			bh_unlock_sock(newsk);
 			sk_free(newsk);
 			return NULL;
 		}