[arch-commits] Commit in linux/trunk (2 files)
Andreas Radke
andyrtr at archlinux.org
Tue Dec 6 12:10:00 UTC 2016
Date: Tuesday, December 6, 2016 @ 12:09:59
Author: andyrtr
Revision: 282875
upgpkg: linux 4.8.12-2
CVE-2016-8655
Added:
linux/trunk/fix_race_condition_in_packet_set_ring.diff
Modified:
linux/trunk/PKGBUILD
--------------------------------------------+
PKGBUILD | 12 ++-
fix_race_condition_in_packet_set_ring.diff | 84 +++++++++++++++++++++++++++
2 files changed, 93 insertions(+), 3 deletions(-)
Modified: PKGBUILD
===================================================================
--- PKGBUILD 2016-12-06 12:07:18 UTC (rev 282874)
+++ PKGBUILD 2016-12-06 12:09:59 UTC (rev 282875)
@@ -6,9 +6,9 @@
#pkgbase=linux-custom # Build kernel with a different name
_srcname=linux-4.8
pkgver=4.8.12
-pkgrel=1
+pkgrel=2
arch=('i686' 'x86_64')
-url="http://www.kernel.org/"
+url="https://www.kernel.org/"
license=('GPL2')
makedepends=('xmlto' 'docbook-xsl' 'kmod' 'inetutils' 'bc' 'libelf')
options=('!strip')
@@ -23,6 +23,7 @@
# standard config files for mkinitcpio ramdisk
'linux.preset'
'change-default-console-loglevel.patch'
+ fix_race_condition_in_packet_set_ring.diff
)
sha256sums=('3e9150065f193d3d94bcf46a1fe9f033c7ef7122ab71d75a7fb5a2f0c9a7e11a'
@@ -33,7 +34,8 @@
'41b9a64542befd2fea170776e8ec22a7d158dd3273633afc9b91662c448cd90a'
'834bd254b56ab71d73f59b3221f056c72f559553c04718e350ab2a3e2991afe0'
'ad6344badc91ad0630caacde83f7f9b97276f80d26a20619a87952be65492c65'
- '1256b241cd477b265a3c2d64bdc19ffe3c9bbcee82ea3994c590c2c76e767d99')
+ '1256b241cd477b265a3c2d64bdc19ffe3c9bbcee82ea3994c590c2c76e767d99'
+ 'ad1ee95f906f88d31fcdb9273cd08e02e8eda177449f0c98dc1bff8cbf1483c2')
validpgpkeys=(
'ABAF11C65A2970B130ABE3C479BE3E4300411886' # Linus Torvalds
'647F28654894E3BD457199BE38DBBDC86092693E' # Greg Kroah-Hartman
@@ -47,6 +49,10 @@
# add upstream patch
patch -p1 -i "${srcdir}/patch-${pkgver}"
+ # fix a race condition that allows to gain root
+ # https://marc.info/?l=linux-netdev&m=148054660230570&w=2
+ patch -p1 -i "${srcdir}/fix_race_condition_in_packet_set_ring.diff"
+
# add latest fixes from stable queue, if needed
# http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git
Added: fix_race_condition_in_packet_set_ring.diff
===================================================================
--- fix_race_condition_in_packet_set_ring.diff (rev 0)
+++ fix_race_condition_in_packet_set_ring.diff 2016-12-06 12:09:59 UTC (rev 282875)
@@ -0,0 +1,84 @@
+From: Philip Pettersson <philip.pettersson at gmail.com>
+
+When packet_set_ring creates a ring buffer it will initialize a
+struct timer_list if the packet version is TPACKET_V3. This value
+can then be raced by a different thread calling setsockopt to
+set the version to TPACKET_V1 before packet_set_ring has finished.
+
+This leads to a use-after-free on a function pointer in the
+struct timer_list when the socket is closed as the previously
+initialized timer will not be deleted.
+
+The bug is fixed by taking lock_sock(sk) in packet_setsockopt when
+changing the packet version while also taking the lock at the start
+of packet_set_ring.
+
+Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
+Signed-off-by: Philip Pettersson <philip.pettersson at gmail.com>
+Signed-off-by: Eric Dumazet <edumazet at google.com>
+---
+ net/packet/af_packet.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
+index d2238b204691b8e4f2e3acb9bc167b553ba32d50..dd2332390c45bbff7c3fc5d259453f2e1ca352bf 100644
+--- a/net/packet/af_packet.c
++++ b/net/packet/af_packet.c
+@@ -3648,19 +3648,25 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
+
+ if (optlen != sizeof(val))
+ return -EINVAL;
+- if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
+- return -EBUSY;
+ if (copy_from_user(&val, optval, sizeof(val)))
+ return -EFAULT;
+ switch (val) {
+ case TPACKET_V1:
+ case TPACKET_V2:
+ case TPACKET_V3:
+- po->tp_version = val;
+- return 0;
++ break;
+ default:
+ return -EINVAL;
+ }
++ lock_sock(sk);
++ if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
++ ret = -EBUSY;
++ } else {
++ po->tp_version = val;
++ ret = 0;
++ }
++ release_sock(sk);
++ return ret;
+ }
+ case PACKET_RESERVE:
+ {
+@@ -4164,6 +4170,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
+ /* Added to avoid minimal code churn */
+ struct tpacket_req *req = &req_u->req;
+
++ lock_sock(sk);
+ /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
+ if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
+ net_warn_ratelimited("Tx-ring is not supported.\n");
+@@ -4245,7 +4252,6 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
+ goto out;
+ }
+
+- lock_sock(sk);
+
+ /* Detach socket from network */
+ spin_lock(&po->bind_lock);
+@@ -4294,11 +4300,11 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
+ if (!tx_ring)
+ prb_shutdown_retire_blk_timer(po, rb_queue);
+ }
+- release_sock(sk);
+
+ if (pg_vec)
+ free_pg_vec(pg_vec, order, req->tp_block_nr);
+ out:
++ release_sock(sk);
+ return err;
+ }
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