netdev - Re: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp

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]

Message-ID: <20180426155134.GA3814@localhost.localdomain>
Date:   Thu, 26 Apr 2018 12:51:34 -0300
From:   Marcelo Ricardo Leitner <marcelo.leitner@...il.com>
To:     Xin Long <lucien.xin@...il.com>
Cc:     network dev <netdev@...r.kernel.org>, linux-sctp@...r.kernel.org,
        davem@...emloft.net, Neil Horman <nhorman@...driver.com>,
        syzkaller@...glegroups.com
Subject: Re: [PATCH net] sctp: handle two v4 addrs comparison in
 sctp_inet6_cmp_addr

On Thu, Apr 26, 2018 at 02:13:57PM +0800, Xin Long wrote:
> Since sctp ipv6 socket also supports v4 addrs, it's possible to
> compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr.
>
> However after Commit 1071ec9d453a ("sctp: do not check port in
> sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which
> in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr
> where it handles them as two v6 addrs. It would cause a out of
> bounds crash.
>
> syzbot found this crash when trying to bind two v4 addrs to a
> v6 socket.
>
> This patch fixes it by adding the process for two v4 addrs in
> sctp_inet6_cmp_addr.
>
> Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr")
> Reported-by: syzbot+cd494c1dd681d4d93ebb@...kaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@...il.com>

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@...il.com>

> ---
>  net/sctp/ipv6.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 2e3f7b7..4224711 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -895,6 +895,9 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
>  	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
>  		return 1;
>
> +	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
> +		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
> +
>  	return __sctp_v6_cmp_addr(addr1, addr2);
>  }
>
> --
> 2.1.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>