4.19-stable patches

added patches:
	net-sctp-fix-race-condition-in-sctp_destroy_sock.patch

diff --git a/queue-4.19/net-sctp-fix-race-condition-in-sctp_destroy_sock.patch b/queue-4.19/net-sctp-fix-race-condition-in-sctp_destroy_sock.patch
new file mode 100644 (file)
index 0000000..4f99d7a
--- /dev/null
+++ b/queue-4.19/net-sctp-fix-race-condition-in-sctp_destroy_sock.patch
@@ -0,0 +1,80 @@
+From b166a20b07382b8bc1dcee2a448715c9c2c81b5b Mon Sep 17 00:00:00 2001
+From: Or Cohen <orcohen@paloaltonetworks.com>
+Date: Tue, 13 Apr 2021 21:10:31 +0300
+Subject: net/sctp: fix race condition in sctp_destroy_sock
+
+From: Or Cohen <orcohen@paloaltonetworks.com>
+
+commit b166a20b07382b8bc1dcee2a448715c9c2c81b5b upstream.
+
+If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock
+held and sp->do_auto_asconf is true, then an element is removed
+from the auto_asconf_splist without any proper locking.
+
+This can happen in the following functions:
+1. In sctp_accept, if sctp_sock_migrate fails.
+2. In inet_create or inet6_create, if there is a bpf program
+   attached to BPF_CGROUP_INET_SOCK_CREATE which denies
+   creation of the sctp socket.
+
+The bug is fixed by acquiring addr_wq_lock in sctp_destroy_sock
+instead of sctp_close.
+
+This addresses CVE-2021-23133.
+
+Reported-by: Or Cohen <orcohen@paloaltonetworks.com>
+Reviewed-by: Xin Long <lucien.xin@gmail.com>
+Fixes: 610236587600 ("bpf: Add new cgroup attach type to enable sock modifications")
+Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com>
+Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/sctp/socket.c |   13 +++++--------
+ 1 file changed, 5 insertions(+), 8 deletions(-)
+
+--- a/net/sctp/socket.c
++++ b/net/sctp/socket.c
+@@ -1569,11 +1569,9 @@ static void sctp_close(struct sock *sk,
+ 
+       /* Supposedly, no process has access to the socket, but
+        * the net layers still may.
+-       * Also, sctp_destroy_sock() needs to be called with addr_wq_lock
+-       * held and that should be grabbed before socket lock.
+        */
+-      spin_lock_bh(&net->sctp.addr_wq_lock);
+-      bh_lock_sock_nested(sk);
++      local_bh_disable();
++      bh_lock_sock(sk);
+ 
+       /* Hold the sock, since sk_common_release() will put sock_put()
+        * and we have just a little more cleanup.
+@@ -1582,7 +1580,7 @@ static void sctp_close(struct sock *sk,
+       sk_common_release(sk);
+ 
+       bh_unlock_sock(sk);
+-      spin_unlock_bh(&net->sctp.addr_wq_lock);
++      local_bh_enable();
+ 
+       sock_put(sk);
+ 
+@@ -4776,9 +4774,6 @@ static int sctp_init_sock(struct sock *s
+       sk_sockets_allocated_inc(sk);
+       sock_prot_inuse_add(net, sk->sk_prot, 1);
+ 
+-      /* Nothing can fail after this block, otherwise
+-       * sctp_destroy_sock() will be called without addr_wq_lock held
+-       */
+       if (net->sctp.default_auto_asconf) {
+               spin_lock(&sock_net(sk)->sctp.addr_wq_lock);
+               list_add_tail(&sp->auto_asconf_list,
+@@ -4813,7 +4808,9 @@ static void sctp_destroy_sock(struct soc
+ 
+       if (sp->do_auto_asconf) {
+               sp->do_auto_asconf = 0;
++              spin_lock_bh(&sock_net(sk)->sctp.addr_wq_lock);
+               list_del(&sp->auto_asconf_list);
++              spin_unlock_bh(&sock_net(sk)->sctp.addr_wq_lock);
+       }
+       sctp_endpoint_free(sp->ep);
+       local_bh_disable();

diff --git a/queue-4.19/series b/queue-4.19/series
index 951a229390b0d22158f518e1be7c697d3493c826..8a8e864e0225b9f5224ab2970052339f2d59e2ef 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -1,3 +1,4 @@
+net-sctp-fix-race-condition-in-sctp_destroy_sock.patch
 input-nspire-keypad-enable-interrupts-only-when-open.patch
 gpio-sysfs-obey-valid_mask.patch
 dmaengine-dw-make-it-dependent-to-has_iomem.patch