* [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr
@ 2018-04-26 6:13 Xin Long
2018-04-26 11:25 ` Neil Horman
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Xin Long @ 2018-04-26 6:13 UTC (permalink / raw)
To: network dev, linux-sctp
Cc: davem, Marcelo Ricardo Leitner, Neil Horman, syzkaller
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@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.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
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr
2018-04-26 6:13 [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Xin Long
@ 2018-04-26 11:25 ` Neil Horman
2018-04-26 15:51 ` Marcelo Ricardo Leitner
2018-04-27 17:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Neil Horman @ 2018-04-26 11:25 UTC (permalink / raw)
To: Xin Long
Cc: network dev, linux-sctp, davem, Marcelo Ricardo Leitner, syzkaller
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@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.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
>
>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr
2018-04-26 6:13 [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Xin Long
2018-04-26 11:25 ` Neil Horman
@ 2018-04-26 15:51 ` Marcelo Ricardo Leitner
2018-04-27 17:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Marcelo Ricardo Leitner @ 2018-04-26 15:51 UTC (permalink / raw)
To: Xin Long; +Cc: network dev, linux-sctp, davem, Neil Horman, syzkaller
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@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.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
>
> --
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>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr
2018-04-26 6:13 [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Xin Long
2018-04-26 11:25 ` Neil Horman
2018-04-26 15:51 ` Marcelo Ricardo Leitner
@ 2018-04-27 17:22 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2018-04-27 17:22 UTC (permalink / raw)
To: lucien.xin; +Cc: netdev, linux-sctp, marcelo.leitner, nhorman, syzkaller
From: Xin Long <lucien.xin@gmail.com>
Date: Thu, 26 Apr 2018 14:13:57 +0800
> 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@syzkaller.appspotmail.com
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
What a long chain we are building of fixes to fixes to fixes... :(
Applied and queued up for -stable, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-04-26 6:13 [PATCH net] sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr Xin Long
2018-04-26 11:25 ` Neil Horman
2018-04-26 15:51 ` Marcelo Ricardo Leitner
2018-04-27 17:22 ` David Miller
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