diff options
Diffstat (limited to 'SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch')
-rw-r--r-- | SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch | 305 |
1 files changed, 0 insertions, 305 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 deleted file mode 100644 index 7eb981e..0000000 --- a/SOURCES/CVE-2020-16119-DCCP-CCID-structure-use-after-free.patch +++ /dev/null @@ -1,305 +0,0 @@ -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 - - |