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From: Tomas Bortoli <tomasbortoli@gmail.com>
To: vyasevich@gmail.com, nhorman@tuxdriver.com, marcelo.leitner@gmail.com
Cc: davem@davemloft.net, linux-sctp@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Tomas Bortoli <tomasbortoli@gmail.com>
Subject: [PATCH] sctp: socket.c validate sprstat_policy
Date: Sat, 27 Oct 2018 22:20:26 +0200	[thread overview]
Message-ID: <20181027202026.32157-1-tomasbortoli@gmail.com> (raw)

It is possible to perform out-of-bound reads on
sctp_getsockopt_pr_streamstatus() and on
sctp_getsockopt_pr_assocstatus() by passing from userspace a
sprstat_policy that overflows the abandoned_sent/abandoned_unsent
fixed length arrays. The over-read data are directly copied/leaked
to userspace.

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
---
v2 - added forgot ||

 net/sctp/socket.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index fc0386e8ff23..5290b8bd40c8 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7083,7 +7083,8 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
 	}
 
 	policy = params.sprstat_policy;
-	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+	    __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
 		goto out;
 
 	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
@@ -7142,7 +7143,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
 	}
 
 	policy = params.sprstat_policy;
-	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+	    __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
 		goto out;
 
 	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
-- 
2.11.0


WARNING: multiple messages have this Message-ID (diff)
From: Tomas Bortoli <tomasbortoli@gmail.com>
To: vyasevich@gmail.com, nhorman@tuxdriver.com, marcelo.leitner@gmail.com
Cc: davem@davemloft.net, linux-sctp@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Tomas Bortoli <tomasbortoli@gmail.com>
Subject: [PATCH] sctp: socket.c validate sprstat_policy
Date: Sat, 27 Oct 2018 20:20:26 +0000	[thread overview]
Message-ID: <20181027202026.32157-1-tomasbortoli@gmail.com> (raw)
In-Reply-To: <20181027195853.30243-1-tomasbortoli@gmail.com>

It is possible to perform out-of-bound reads on
sctp_getsockopt_pr_streamstatus() and on
sctp_getsockopt_pr_assocstatus() by passing from userspace a
sprstat_policy that overflows the abandoned_sent/abandoned_unsent
fixed length arrays. The over-read data are directly copied/leaked
to userspace.

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+5da0d0a72a9e7d791748@syzkaller.appspotmail.com
---
v2 - added forgot ||

 net/sctp/socket.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index fc0386e8ff23..5290b8bd40c8 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7083,7 +7083,8 @@ static int sctp_getsockopt_pr_assocstatus(struct sock *sk, int len,
 	}
 
 	policy = params.sprstat_policy;
-	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+	    __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
 		goto out;
 
 	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
@@ -7142,7 +7143,8 @@ static int sctp_getsockopt_pr_streamstatus(struct sock *sk, int len,
 	}
 
 	policy = params.sprstat_policy;
-	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)))
+	if (!policy || (policy & ~(SCTP_PR_SCTP_MASK | SCTP_PR_SCTP_ALL)) ||
+	    __SCTP_PR_INDEX(policy) > SCTP_PR_INDEX(MAX))
 		goto out;
 
 	asoc = sctp_id2assoc(sk, params.sprstat_assoc_id);
-- 
2.11.0

             reply	other threads:[~2018-10-27 20:20 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-27 20:20 Tomas Bortoli [this message]
2018-10-27 20:20 ` [PATCH] sctp: socket.c validate sprstat_policy Tomas Bortoli
2018-10-27 20:43 ` Tomas Bortoli
2018-10-27 20:43   ` Tomas Bortoli
2018-10-28  0:03   ` David Miller
2018-10-28  0:03     ` David Miller
  -- strict thread matches above, loose matches on Subject: below --
2018-10-27 19:58 Tomas Bortoli
2018-10-27 19:58 ` Tomas Bortoli
2018-10-27 20:50 ` kbuild test robot
2018-10-27 20:50   ` kbuild test robot
2018-10-27 20:53 ` kbuild test robot
2018-10-27 20:53   ` kbuild test robot

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