From 91a7ba9320a34546ff5ea72ea2ad7ceb761f6f1b Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 16 Nov 2017 18:12:24 +0000 Subject: [PATCH] net: cdc_ether: fix divide by 0 on bad descriptors (CVE-2017-16649) --- debian/changelog | 1 + ...r-fix-divide-by-0-on-bad-descriptors.patch | 31 +++++++++++++++++++ debian/patches/series | 1 + 3 files changed, 33 insertions(+) create mode 100644 debian/patches/bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch diff --git a/debian/changelog b/debian/changelog index 2973a83e3..b2eafdfea 100644 --- a/debian/changelog +++ b/debian/changelog @@ -130,6 +130,7 @@ linux (4.13.13-1) UNRELEASED; urgency=medium * media: imon: Fix null-ptr-deref in imon_probe (CVE-2017-16537) * media: dib0700: fix invalid dvb_detach argument (CVE-2017-16646) * net: usb: asix: fill null-ptr-deref in asix_suspend (CVE-2017-16647) + * net: cdc_ether: fix divide by 0 on bad descriptors (CVE-2017-16649) -- Salvatore Bonaccorso Sat, 04 Nov 2017 09:54:41 +0100 diff --git a/debian/patches/bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch b/debian/patches/bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch new file mode 100644 index 000000000..b9b5a2830 --- /dev/null +++ b/debian/patches/bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch @@ -0,0 +1,31 @@ +From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= +Date: Mon, 6 Nov 2017 15:37:22 +0100 +Subject: net: cdc_ether: fix divide by 0 on bad descriptors +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit +Origin: https://git.kernel.org/linus/2cb80187ba065d7decad7c6614e35e07aec8a974 +Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-16649 + +Setting dev->hard_mtu to 0 will cause a divide error in +usbnet_probe. Protect against devices with bogus CDC Ethernet +functional descriptors by ignoring a zero wMaxSegmentSize. + +Signed-off-by: Bjørn Mork +Acked-by: Oliver Neukum +Signed-off-by: David S. Miller +--- + drivers/net/usb/cdc_ether.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/net/usb/cdc_ether.c ++++ b/drivers/net/usb/cdc_ether.c +@@ -221,7 +221,7 @@ skip: + goto bad_desc; + } + +- if (header.usb_cdc_ether_desc) { ++ if (header.usb_cdc_ether_desc && info->ether->wMaxSegmentSize) { + dev->hard_mtu = le16_to_cpu(info->ether->wMaxSegmentSize); + /* because of Zaurus, we may be ignoring the host + * side link address we were given. diff --git a/debian/patches/series b/debian/patches/series index 11f4defd9..c645ce43c 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -122,6 +122,7 @@ bugfix/all/media-cx231xx-cards-fix-null-deref-on-missing-associ.patch bugfix/all/media-imon-fix-null-ptr-deref-in-imon_probe.patch bugfix/all/media-dib0700-fix-invalid-dvb_detach-argument.patch bugfix/all/net-usb-asix-fill-null-ptr-deref-in-asix_suspend.patch +bugfix/all/net-cdc_ether-fix-divide-by-0-on-bad-descriptors.patch # Fix exported symbol versions bugfix/alpha/alpha-restore-symbol-versions-for-symbols-exported-f.patch