[PATCH 3.19.y-ckt 11/66] macvtap: always pass ethernet header in linear

From	Kamal Mostafa <kamal@canonical.com>
Newsgroups	linux.kernel
Subject	[PATCH 3.19.y-ckt 11/66] macvtap: always pass ethernet header in linear
Date	2016-04-26 22:50 +0200
Message-ID	<rsi5I-5Mq-7@gated-at.bofh.it> (permalink)
References	<rshMl-5Dx-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.19.8-ckt20 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Willem de Bruijn <willemb@google.com>

[ Upstream commit 8e2ad4113ce4671686740f808ff2795395c39eef ]

The stack expects link layer headers in the skb linear section.
Macvtap can create skbs with llheader in frags in edge cases:
when (IFF_VNET_HDR is off or vnet_hdr.hdr_len < ETH_HLEN) and
prepad + len > PAGE_SIZE and vnet_hdr.flags has no or bad csum.

Add checks to ensure linear is always at least ETH_HLEN.
At this point, len is already ensured to be >= ETH_HLEN.

For backwards compatiblity, rounds up short vnet_hdr.hdr_len.
This differs from tap and packet, which return an error.

Fixes b9fb9ee07e67 ("macvtap: add GSO/csum offload support")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/net/macvtap.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 73437568..005a407 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -710,6 +710,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 			macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
 		if (copylen > good_linear)
 			copylen = good_linear;
+		else if (copylen < ETH_HLEN)
+			copylen = ETH_HLEN;
 		linear = copylen;
 		i = *from;
 		iov_iter_advance(&i, copylen);
@@ -719,10 +721,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
 	if (!zerocopy) {
 		copylen = len;
-		if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
+		linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
+		if (linear > good_linear)
 			linear = good_linear;
-		else
-			linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
+		else if (linear < ETH_HLEN)
+			linear = ETH_HLEN;
 	}
 
 	skb = macvtap_alloc_skb(&q->sk, MACVTAP_RESERVE, copylen,
-- 
2.7.4

Thread

[3.19.y-ckt stable] Linux 3.19.8-ckt20 stable review Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 09/66] net: validate variable length ll headers Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 53/66] x86/mm/xen: Suppress hugetlbfs in PV guests Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 63/66] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 45/66] drm/radeon: add a quirk for a XFX R9 270X Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 62/66] net: bcmgenet: device stats are unsigned long Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 21/66] ARM: OMAP2+: hwmod: Fix updating of sysconfig register Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:30 +0200
  [PATCH 3.19.y-ckt 38/66] crypto: sha1-mb - use corrcet pointer while completing jobs Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 44/66] powerpc: Update TM user feature bits in scan_features() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 18/66] ipv4: l2tp: fix a potential issue in l2tp_ip_recv Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 33/66] usb: xhci: fix wild pointers in xhci_mem_cleanup Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 39/66] crypto: ccp - Prevent information leakage on export Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 43/66] powerpc: Update cpu_user_features2 in scan_features() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 48/66] ALSA: pcxhr: Fix missing mutex unlock Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 47/66] futex: Acknowledge a new waiter in counter before plist Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 36/66] USB: uas: Add a new NO_REPORT_LUNS quirk Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 50/66] drm/radeon: forbid mapping of userptr bo through radeon device file Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 34/66] usb: xhci: fix xhci locking up during hcd remove Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 46/66] futex: Handle unlock_pi race gracefully Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 30/66] usb: xhci: applying XHCI_PME_STUCK_QUIRK to Intel BXT B0 host Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 35/66] xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 27/66] ALSA: hda - Fix regression of monitor_present flag in eld proc file Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 22/66] drm/qxl: fix cursor position with non-zero hotspot Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 42/66] powerpc: scan_features() updates incorrect bits for REAL_LE Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 23/66] Input: gtco - fix crash on detecting device without endpoints Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 41/66] ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 59/66] bpf/verifier: reject invalid LD_ABS | BPF_DW instruction Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 31/66] xhci: resume USB 3 roothub first Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 37/66] usb: hcd: out of bounds access in for_each_companion Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 32/66] usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 29/66] lib: lz4: fixed zram with lz4 on big endian machines Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 40/66] video: ARM CLCD: runtime check for Versatile Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 26/66] nl80211: check netlink protocol in socket release notification Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 28/66] dmaengine: dw: fix master selection Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 25/66] ALSA: usb-audio: Skip volume controls triggers hangup on Dell USB Dock Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:40 +0200
  [PATCH 3.19.y-ckt 08/66] udp6: fix UDP/IPv6 encap resubmit path Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 11/66] macvtap: always pass ethernet header in linear Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 16/66] qmi_wwan: add "D-Link DWM-221 B1" device id Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 10/66] sh_eth: fix NULL pointer dereference in sh_eth_ring_format() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 01/66] usbnet: cleanup after bind() in probe() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 05/66] sctp: lack the check for ports in sctp_v6_cmp_addr Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 02/66] tunnel: Clear IPCB(skb)->opt before dst_link_failure called Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 04/66] net: qca_spi: clear IFF_TX_SKB_SHARING Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 17/66] rtnl: fix msg size calculation in if_nlmsg_size() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 15/66] xfrm: Fix crash observed during device unregistration and decryption Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 20/66] HID: usbhid: fix inconsistent reset/resume/reset-resume behavior Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 14/66] bonding: fix bond_get_stats() Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 07/66] cdc_ncm: toggle altsetting to force reset before setup Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 19/66] ipv6: l2tp: fix a potential issue in l2tp_ip6_recv Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 12/66] farsync: fix off-by-one bug in fst_add_one Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200
  [PATCH 3.19.y-ckt 06/66] qmi_wwan: add Sierra Wireless EM74xx device ID Kamal Mostafa <kamal@canonical.com> - 2016-04-26 22:50 +0200

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