diff mbox series

[4.9,21/80] macsec: avoid to set wrong mtu

Message ID	20200501131521.178970534@linuxfoundation.org
State	Superseded
Headers	show Return-Path: <SRS0=1/SS=6P=vger.kernel.org=stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Taehee Yoo <ap420073@gmail.com>, "David S. Miller" <davem@davemloft.net> Subject: [PATCH 4.9 21/80] macsec: avoid to set wrong mtu Date: Fri, 1 May 2020 15:21:15 +0200 Message-Id: <20200501131521.178970534@linuxfoundation.org> In-Reply-To: <20200501131513.810761598@linuxfoundation.org> References: <20200501131513.810761598@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk
Series	None \| expand [4.9,02/80] net: ipv4: emulate READ_ONCE() on ->hdrincl bit-field in raw_sendmsg() [4.9,05/80] crypto: mxs-dcp - make symbols sha1_null_hash and sha256_null_hash static [4.9,06/80] vti4: removed duplicate log message. [4.9,10/80] ceph: dont skip updating wanted caps when cap is stale [4.9,11/80] pwm: rcar: Fix late Runtime PM enablement [4.9,13/80] ASoC: Intel: atom: Take the drv->lock mutex before calling sst_send_slot_map() [4.9,14/80] kernel/gcov/fs.c: gcov_seq_next() should increase position index [4.9,19/80] PCI/ASPM: Allow re-enabling Clock PM [4.9,20/80] ipv6: fix restrict IPV6_ADDRFORM operation [4.9,21/80] macsec: avoid to set wrong mtu [4.9,22/80] macvlan: fix null dereference in macvlan_device_event() [4.9,23/80] net: netrom: Fix potential nr_neigh refcnt leak in nr_add_node [4.9,25/80] tcp: cache line align MAX_TCP_HEADER [4.9,27/80] net: dsa: b53: Fix ARL register definitions [4.9,28/80] xfrm: Always set XFRM_TRANSFORMED in xfrm{4,6}_output_finish [4.9,31/80] iio: xilinx-xadc: Fix clearing interrupt when enabling trigger [4.9,32/80] iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode [4.9,38/80] overflow.h: Add arithmetic shift helper [4.9,41/80] ALSA: usb-audio: Fix usb audio refcnt leak when getting spdif [4.9,43/80] tpm/tpm_tis: Free IRQ if probing fails [4.9,44/80] KVM: Check validity of resolved slot when searching memslots [4.9,45/80] KVM: VMX: Enable machine check support for 32bit targets [4.9,46/80] tty: hvc: fix buffer overflow during hvc_alloc(). [4.9,48/80] usb-storage: Add unusual_devs entry for JMicron JMS566 [4.9,54/80] staging: vt6656: Fix drivers TBTT timing counter. [4.9,55/80] staging: vt6656: Power save stop wake_up_count wrap around. [4.9,57/80] UAS: fix deadlock in error handling and PM flushing work [4.9,59/80] remoteproc: Fix wrong rvring index computation [4.9,60/80] fuse: fix possibly missed wake-up after abort [4.9,63/80] nfsd: memory corruption in nfsd4_lock() [4.9,64/80] net/cxgb4: Check the return from t4_query_params properly [4.9,65/80] perf/core: fix parent pid/tid in task exit events [4.9,66/80] bpf, x86: Fix encoding for lower 8-bit registers in BPF_STX BPF_B [4.9,68/80] scsi: target: fix PR IN / READ FULL STATUS for FC [4.9,69/80] objtool: Fix CONFIG_UBSAN_TRAP unreachable warnings [4.9,71/80] xen/xenbus: ensure xenbus_map_ring_valloc() returns proper grant status [4.9,74/80] hwmon: (jc42) Fix name to have no illegal characters [4.9,77/80] ext4: dont perform block validity checks on the journal inode [4.9,79/80] ext4: unsigned int compared against zero

Commit Message

Greg KH May 1, 2020, 1:21 p.m. UTC

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 7f327080364abccf923fa5a5b24e038eb0ba1407 ]

When a macsec interface is created, the mtu is calculated with the lower
interface's mtu value.
If the mtu of lower interface is lower than the length, which is needed
by macsec interface, macsec's mtu value will be overflowed.
So, if the lower interface's mtu is too low, macsec interface's mtu
should be set to 0.

Test commands:
    ip link add dummy0 mtu 10 type dummy
    ip link add macsec0 link dummy0 type macsec
    ip link show macsec0

Before:
    11: macsec0@dummy0: <BROADCAST,MULTICAST,M-DOWN> mtu 4294967274
After:
    11: macsec0@dummy0: <BROADCAST,MULTICAST,M-DOWN> mtu 0

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/macsec.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff mbox series

Patch

--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3209,11 +3209,11 @@  static int macsec_newlink(struct net *ne
 			  struct nlattr *tb[], struct nlattr *data[])
 {
 	struct macsec_dev *macsec = macsec_priv(dev);
+	rx_handler_func_t *rx_handler;
+	u8 icv_len = DEFAULT_ICV_LEN;
 	struct net_device *real_dev;
-	int err;
+	int err, mtu;
 	sci_t sci;
-	u8 icv_len = DEFAULT_ICV_LEN;
-	rx_handler_func_t *rx_handler;
 
 	if (!tb[IFLA_LINK])
 		return -EINVAL;
@@ -3229,7 +3229,11 @@  static int macsec_newlink(struct net *ne
 
 	if (data && data[IFLA_MACSEC_ICV_LEN])
 		icv_len = nla_get_u8(data[IFLA_MACSEC_ICV_LEN]);
-	dev->mtu = real_dev->mtu - icv_len - macsec_extra_len(true);
+	mtu = real_dev->mtu - icv_len - macsec_extra_len(true);
+	if (mtu < 0)
+		dev->mtu = 0;
+	else
+		dev->mtu = mtu;
 
 	rx_handler = rtnl_dereference(real_dev->rx_handler);
 	if (rx_handler && rx_handler != macsec_handle_frame)