path: root/net
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authorR. Parameswaran <parameswaran.r7@gmail.com>2017-04-12 18:31:04 -0700
committerDavid S. Miller <davem@davemloft.net>2017-04-17 13:01:48 -0400
commit57240d007816486131bee88cd474c2a71f0fe224 (patch)
treeeb6a94027fd814fd1a468ee127340b6201056bfd /net
parentnet: ipv6: send unsolicited NA on admin up (diff)
l2tp: device MTU setup, tunnel socket needs a lock
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>
Diffstat (limited to '')
2 files changed, 3 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 138566a63123..b722d559c544 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -225,7 +225,9 @@ static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
dev->needed_headroom += session->hdr_len;
+ 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
diff --git a/net/socket.c b/net/socket.c
index eea997036ada..c2564eb25c6b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -3360,7 +3360,7 @@ 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)