kernel 5.8.15

1 files changed, 305 insertions, 0 deletions

diff --git a/SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch b/SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch
new file mode 100644
index 0000000..7eb981e
--- /dev/null
+++ b/SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch
@@ -0,0 +1,305 @@
+From MAILER-DAEMON Wed Oct 14 16:34:37 2020
+From: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
+To: netdev@vger.kernel.org
+Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>, "David S. Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, Thadeu Lima de Souza Cascardo <cascardo@canonical.com>, "Gustavo A. R. Silva" <gustavoars@kernel.org>, "Alexander A. Klimov" <grandmaster@al2klimov.de>, Kees Cook <keescook@chromium.org>, Eric Dumazet <edumazet@google.com>, Alexey Kodanev <alexey.kodanev@oracle.com>, dccp@vger.kernel.org, linux-kernel@vger.kernel.org
+Subject: [PATCH 1/2] dccp: ccid: move timers to struct dccp_sock
+Date: Tue, 13 Oct 2020 19:18:48 +0200
+Message-Id: <20201013171849.236025-2-kleber.souza@canonical.com>
+In-Reply-To: <20201013171849.236025-1-kleber.souza@canonical.com>
+References: <20201013171849.236025-1-kleber.souza@canonical.com>
+List-ID: <linux-kernel.vger.kernel.org>
+X-Mailing-List: linux-kernel@vger.kernel.org
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 7bit
+
+From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
+
+When dccps_hc_tx_ccid is freed, ccid timers may still trigger. The reason
+del_timer_sync can't be used is because this relies on keeping a reference
+to struct sock. But as we keep a pointer to dccps_hc_tx_ccid and free that
+during disconnect, the timer should really belong to struct dccp_sock.
+
+This addresses CVE-2020-16119.
+
+Fixes: 839a6094140a (net: dccp: Convert timers to use timer_setup())
+Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
+Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
+Acked-bd: Richard Sailer <richard_siegfried@systemli.org>
+---
+ include/linux/dccp.h   |  2 ++
+ net/dccp/ccids/ccid2.c | 32 +++++++++++++++++++-------------
+ net/dccp/ccids/ccid3.c | 30 ++++++++++++++++++++----------
+ 3 files changed, 41 insertions(+), 23 deletions(-)
+
+diff --git a/include/linux/dccp.h b/include/linux/dccp.h
+index 07e547c02fd8..504afa1a4be6 100644
+--- a/include/linux/dccp.h
++++ b/include/linux/dccp.h
+@@ -259,6 +259,7 @@ struct dccp_ackvec;
+  * @dccps_sync_scheduled - flag which signals "send out-of-band message soon"
+  * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets
+  * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing)
++ * @dccps_ccid_timer - used by the CCIDs
+  * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
+  */
+ struct dccp_sock {
+@@ -303,6 +304,7 @@ struct dccp_sock {
+ 	__u8				dccps_sync_scheduled:1;
+ 	struct tasklet_struct		dccps_xmitlet;
+ 	struct timer_list		dccps_xmit_timer;
++	struct timer_list		dccps_ccid_timer;
+ };
+ 
+ static inline struct dccp_sock *dccp_sk(const struct sock *sk)
+diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
+index 3da1f77bd039..dbca1f1e2449 100644
+--- a/net/dccp/ccids/ccid2.c
++++ b/net/dccp/ccids/ccid2.c
+@@ -126,21 +126,26 @@ static void dccp_tasklet_schedule(struct sock *sk)
+ 
+ static void ccid2_hc_tx_rto_expire(struct timer_list *t)
+ {
+-	struct ccid2_hc_tx_sock *hc = from_timer(hc, t, tx_rtotimer);
+-	struct sock *sk = hc->sk;
+-	const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
++	struct dccp_sock *dp = from_timer(dp, t, dccps_ccid_timer);
++	struct sock *sk = (struct sock *)dp;
++	struct ccid2_hc_tx_sock *hc;
++	bool sender_was_blocked;
+ 
+ 	bh_lock_sock(sk);
++
++	if (inet_sk_state_load(sk) == DCCP_CLOSED)
++		goto out;
++
++	hc = ccid_priv(dp->dccps_hc_tx_ccid);
++	sender_was_blocked = ccid2_cwnd_network_limited(hc);
++
+ 	if (sock_owned_by_user(sk)) {
+-		sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + HZ / 5);
++		sk_reset_timer(sk, &dp->dccps_ccid_timer, jiffies + HZ / 5);
+ 		goto out;
+ 	}
+ 
+ 	ccid2_pr_debug("RTO_EXPIRE\n");
+ 
+-	if (sk->sk_state == DCCP_CLOSED)
+-		goto out;
+-
+ 	/* back-off timer */
+ 	hc->tx_rto <<= 1;
+ 	if (hc->tx_rto > DCCP_RTO_MAX)
+@@ -166,7 +171,7 @@ static void ccid2_hc_tx_rto_expire(struct timer_list *t)
+ 	if (sender_was_blocked)
+ 		dccp_tasklet_schedule(sk);
+ 	/* restart backed-off timer */
+-	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
++	sk_reset_timer(sk, &dp->dccps_ccid_timer, jiffies + hc->tx_rto);
+ out:
+ 	bh_unlock_sock(sk);
+ 	sock_put(sk);
+@@ -330,7 +335,7 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len)
+ 	}
+ #endif
+ 
+-	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
++	sk_reset_timer(sk, &dp->dccps_ccid_timer, jiffies + hc->tx_rto);
+ 
+ #ifdef CONFIG_IP_DCCP_CCID2_DEBUG
+ 	do {
+@@ -700,9 +705,9 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+ 
+ 	/* restart RTO timer if not all outstanding data has been acked */
+ 	if (hc->tx_pipe == 0)
+-		sk_stop_timer(sk, &hc->tx_rtotimer);
++		sk_stop_timer(sk, &dp->dccps_ccid_timer);
+ 	else
+-		sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
++		sk_reset_timer(sk, &dp->dccps_ccid_timer, jiffies + hc->tx_rto);
+ done:
+ 	/* check if incoming Acks allow pending packets to be sent */
+ 	if (sender_was_blocked && !ccid2_cwnd_network_limited(hc))
+@@ -737,17 +742,18 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
+ 	hc->tx_last_cong = hc->tx_lsndtime = hc->tx_cwnd_stamp = ccid2_jiffies32;
+ 	hc->tx_cwnd_used = 0;
+ 	hc->sk		 = sk;
+-	timer_setup(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, 0);
++	timer_setup(&dp->dccps_ccid_timer, ccid2_hc_tx_rto_expire, 0);
+ 	INIT_LIST_HEAD(&hc->tx_av_chunks);
+ 	return 0;
+ }
+ 
+ static void ccid2_hc_tx_exit(struct sock *sk)
+ {
++	struct dccp_sock *dp = dccp_sk(sk);
+ 	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+ 	int i;
+ 
+-	sk_stop_timer(sk, &hc->tx_rtotimer);
++	sk_stop_timer(sk, &dp->dccps_ccid_timer);
+ 
+ 	for (i = 0; i < hc->tx_seqbufc; i++)
+ 		kfree(hc->tx_seqbuf[i]);
+diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
+index b9ee1a4a8955..685f4d046c0d 100644
+--- a/net/dccp/ccids/ccid3.c
++++ b/net/dccp/ccids/ccid3.c
+@@ -184,17 +184,24 @@ static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc,
+ 
+ static void ccid3_hc_tx_no_feedback_timer(struct timer_list *t)
+ {
+-	struct ccid3_hc_tx_sock *hc = from_timer(hc, t, tx_no_feedback_timer);
+-	struct sock *sk = hc->sk;
++	struct dccp_sock *dp = from_timer(dp, t, dccps_ccid_timer);
++	struct ccid3_hc_tx_sock *hc;
++	struct sock *sk = (struct sock *)dp;
+ 	unsigned long t_nfb = USEC_PER_SEC / 5;
+ 
+ 	bh_lock_sock(sk);
++
++	if (inet_sk_state_load(sk) == DCCP_CLOSED)
++		goto out;
++
+ 	if (sock_owned_by_user(sk)) {
+ 		/* Try again later. */
+ 		/* XXX: set some sensible MIB */
+ 		goto restart_timer;
+ 	}
+ 
++	hc = ccid_priv(dp->dccps_hc_tx_ccid);
++
+ 	ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk,
+ 		       ccid3_tx_state_name(hc->tx_state));
+ 
+@@ -250,8 +257,8 @@ static void ccid3_hc_tx_no_feedback_timer(struct timer_list *t)
+ 		t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi);
+ 
+ restart_timer:
+-	sk_reset_timer(sk, &hc->tx_no_feedback_timer,
+-			   jiffies + usecs_to_jiffies(t_nfb));
++	sk_reset_timer(sk, &dp->dccps_ccid_timer,
++		       jiffies + usecs_to_jiffies(t_nfb));
+ out:
+ 	bh_unlock_sock(sk);
+ 	sock_put(sk);
+@@ -280,7 +287,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
+ 		return -EBADMSG;
+ 
+ 	if (hc->tx_state == TFRC_SSTATE_NO_SENT) {
+-		sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies +
++		sk_reset_timer(sk, &dp->dccps_ccid_timer, (jiffies +
+ 			       usecs_to_jiffies(TFRC_INITIAL_TIMEOUT)));
+ 		hc->tx_last_win_count	= 0;
+ 		hc->tx_t_last_win_count = now;
+@@ -354,6 +361,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len)
+ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+ {
+ 	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
++	struct dccp_sock *dp = dccp_sk(sk);
+ 	struct tfrc_tx_hist_entry *acked;
+ 	ktime_t now;
+ 	unsigned long t_nfb;
+@@ -420,7 +428,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+ 			       (unsigned int)(hc->tx_x >> 6));
+ 
+ 	/* unschedule no feedback timer */
+-	sk_stop_timer(sk, &hc->tx_no_feedback_timer);
++	sk_stop_timer(sk, &dp->dccps_ccid_timer);
+ 
+ 	/*
+ 	 * As we have calculated new ipi, delta, t_nom it is possible
+@@ -445,8 +453,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+ 		       "expire in %lu jiffies (%luus)\n",
+ 		       dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb);
+ 
+-	sk_reset_timer(sk, &hc->tx_no_feedback_timer,
+-			   jiffies + usecs_to_jiffies(t_nfb));
++	sk_reset_timer(sk, &dp->dccps_ccid_timer,
++		       jiffies + usecs_to_jiffies(t_nfb));
+ }
+ 
+ static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type,
+@@ -488,21 +496,23 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type,
+ 
+ static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk)
+ {
++	struct dccp_sock *dp = dccp_sk(sk);
+ 	struct ccid3_hc_tx_sock *hc = ccid_priv(ccid);
+ 
+ 	hc->tx_state = TFRC_SSTATE_NO_SENT;
+ 	hc->tx_hist  = NULL;
+ 	hc->sk	     = sk;
+-	timer_setup(&hc->tx_no_feedback_timer,
++	timer_setup(&dp->dccps_ccid_timer,
+ 		    ccid3_hc_tx_no_feedback_timer, 0);
+ 	return 0;
+ }
+ 
+ static void ccid3_hc_tx_exit(struct sock *sk)
+ {
++	struct dccp_sock *dp = dccp_sk(sk);
+ 	struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
+ 
+-	sk_stop_timer(sk, &hc->tx_no_feedback_timer);
++	sk_stop_timer(sk, &dp->dccps_ccid_timer);
+ 	tfrc_tx_hist_purge(&hc->tx_hist);
+ }
+ 
+-- 
+2.25.1
+
+
+From MAILER-DAEMON Wed Oct 14 16:34:37 2020
+From: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
+To: netdev@vger.kernel.org
+Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>, "David S. Miller" <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org>, Thadeu Lima de Souza Cascardo <cascardo@canonical.com>, "Gustavo A. R. Silva" <gustavoars@kernel.org>, "Alexander A. Klimov" <grandmaster@al2klimov.de>, Kees Cook <keescook@chromium.org>, Eric Dumazet <edumazet@google.com>, Alexey Kodanev <alexey.kodanev@oracle.com>, dccp@vger.kernel.org, linux-kernel@vger.kernel.org
+Subject: [PATCH 2/2] Revert "dccp: don't free ccid2_hc_tx_sock struct in dccp_disconnect()"
+Date: Tue, 13 Oct 2020 19:18:49 +0200
+Message-Id: <20201013171849.236025-3-kleber.souza@canonical.com>
+In-Reply-To: <20201013171849.236025-1-kleber.souza@canonical.com>
+References: <20201013171849.236025-1-kleber.souza@canonical.com>
+List-ID: <linux-kernel.vger.kernel.org>
+X-Mailing-List: linux-kernel@vger.kernel.org
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 7bit
+
+From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
+
+This reverts commit 2677d20677314101293e6da0094ede7b5526d2b1.
+
+This fixes an issue that after disconnect, dccps_hc_tx_ccid will still be
+kept, allowing the socket to be reused as a listener socket, and the cloned
+socket will free its dccps_hc_tx_ccid, leading to a later use after free,
+when the listener socket is closed.
+
+This addresses CVE-2020-16119.
+
+Fixes: 2677d2067731 (dccp: don't free ccid2_hc_tx_sock struct in dccp_disconnect())
+Reported-by: Hadar Manor
+Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
+Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
+Acked-by: Richard Sailer <richard_siegfried@systemli.org>
+---
+ net/dccp/proto.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/net/dccp/proto.c b/net/dccp/proto.c
+index 6d705d90c614..359e848dba6c 100644
+--- a/net/dccp/proto.c
++++ b/net/dccp/proto.c
+@@ -279,7 +279,9 @@ int dccp_disconnect(struct sock *sk, int flags)
+ 
+ 	dccp_clear_xmit_timers(sk);
+ 	ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
++	ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
+ 	dp->dccps_hc_rx_ccid = NULL;
++	dp->dccps_hc_tx_ccid = NULL;
+ 
+ 	__skb_queue_purge(&sk->sk_receive_queue);
+ 	__skb_queue_purge(&sk->sk_write_queue);
+-- 
+2.25.1
+
+