From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sun, 24 May 2020 09:54:09 +0000 (+0200)
Subject: 4.9-stable patches
X-Git-Tag: v4.4.225~41
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=14b00aa0f54b7ee93fe8f70498238f616626d8d9;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	l2tp-device-mtu-setup-tunnel-socket-needs-a-lock.patch
---

diff --git a/queue-4.9/l2tp-device-mtu-setup-tunnel-socket-needs-a-lock.patch b/queue-4.9/l2tp-device-mtu-setup-tunnel-socket-needs-a-lock.patch
new file mode 100644
index 00000000000..6e9d496f1ee
--- /dev/null
+++ b/queue-4.9/l2tp-device-mtu-setup-tunnel-socket-needs-a-lock.patch
@@ -0,0 +1,62 @@
+From 57240d007816486131bee88cd474c2a71f0fe224 Mon Sep 17 00:00:00 2001
+From: "R. Parameswaran" <parameswaran.r7@gmail.com>
+Date: Wed, 12 Apr 2017 18:31:04 -0700
+Subject: l2tp: device MTU setup, tunnel socket needs a lock
+
+From: R. Parameswaran <parameswaran.r7@gmail.com>
+
+commit 57240d007816486131bee88cd474c2a71f0fe224 upstream.
+
+The MTU overhead calculation in L2TP device set-up
+merged via commit b784e7ebfce8cfb16c6f95e14e8532d0768ab7ff
+needs to be adjusted to lock the tunnel socket while
+referencing the sub-data structures to derive the
+socket's IP overhead.
+
+Reported-by: Guillaume Nault <g.nault@alphalink.fr>
+Tested-by: Guillaume Nault <g.nault@alphalink.fr>
+Signed-off-by: R. Parameswaran <rparames@brocade.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Cc: Giuliano Procida <gprocida@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/net.h |    2 +-
+ net/l2tp/l2tp_eth.c |    2 ++
+ net/socket.c        |    2 +-
+ 3 files changed, 4 insertions(+), 2 deletions(-)
+
+--- a/include/linux/net.h
++++ b/include/linux/net.h
+@@ -298,7 +298,7 @@ int kernel_sendpage(struct socket *sock,
+ int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg);
+ int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how);
+ 
+-/* Following routine returns the IP overhead imposed by a socket.  */
++/* Routine returns the IP overhead imposed by a (caller-protected) socket. */
+ u32 kernel_sock_ip_overhead(struct sock *sk);
+ 
+ #define MODULE_ALIAS_NETPROTO(proto) \
+--- a/net/l2tp/l2tp_eth.c
++++ b/net/l2tp/l2tp_eth.c
+@@ -240,7 +240,9 @@ static void l2tp_eth_adjust_mtu(struct l
+ 		dev->needed_headroom += session->hdr_len;
+ 		return;
+ 	}
++	lock_sock(tunnel->sock);
+ 	l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
++	release_sock(tunnel->sock);
+ 	if (l3_overhead == 0) {
+ 		/* L3 Overhead couldn't be identified, this could be
+ 		 * because tunnel->sock was NULL or the socket's
+--- a/net/socket.c
++++ b/net/socket.c
+@@ -3325,7 +3325,7 @@ EXPORT_SYMBOL(kernel_sock_shutdown);
+ /* This routine returns the IP overhead imposed by a socket i.e.
+  * the length of the underlying IP header, depending on whether
+  * this is an IPv4 or IPv6 socket and the length from IP options turned
+- * on at the socket.
++ * on at the socket. Assumes that the caller has a lock on the socket.
+  */
+ u32 kernel_sock_ip_overhead(struct sock *sk)
+ {
diff --git a/queue-4.9/series b/queue-4.9/series
index 1369e949e64..890d9f974e9 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -48,3 +48,4 @@ l2tp-protect-sock-pointer-of-struct-pppol2tp_session-with-rcu.patch
 l2tp-initialise-ppp-sessions-before-registering-them.patch
 alsa-pcm-fix-incorrect-hw_base-increase.patch
 dmaengine-tegra210-adma-fix-an-error-handling-path-in-tegra_adma_probe.patch
+l2tp-device-mtu-setup-tunnel-socket-needs-a-lock.patch