commit:     db24a13c10ab6eb294f0ac692702cd67868d374e
Author:     Mike Pagano <mpagano <AT> gentoo <DOT> org>
AuthorDate: Fri Dec  9 00:41:37 2016 +0000
Commit:     Mike Pagano <mpagano <AT> gentoo <DOT> org>
CommitDate: Fri Dec  9 00:41:37 2016 +0000
URL:        https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=db24a13c

Fix race condition in packet_set_ring. CVE-2016-8655. Bug #601926.

 0000_README                                      |  4 ++
 1520_fix-race-condition-in-packet-set-ring.patch | 62 ++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/0000_README b/0000_README
index b783e9c..866b122 100644
--- a/0000_README
+++ b/0000_README
@@ -326,6 +326,10 @@ Patch:  
1510_fs-enable-link-security-restrictions-by-default.patch
 From:   
http://sources.debian.net/src/linux/3.16.7-ckt4-3/debian/patches/debian/fs-enable-link-security-restrictions-by-default.patch/
 Desc:   Enable link security restrictions by default
 
+Patch:  1520_fix-race-condition-in-packet-set-ring.patch
+From:   
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=84ac7260236a49c79eede91617700174c2c19b0c
+Desc:   packet: fix race condition in packet_set_ring. CVE-2016-8655. Bug 
#601926.
+
 Patch:  1700_enable-thinkpad-micled.patch
 From:   https://bugs.gentoo.org/show_bug.cgi?id=449248
 Desc:   Enable mic mute led in thinkpads

diff --git a/1520_fix-race-condition-in-packet-set-ring.patch 
b/1520_fix-race-condition-in-packet-set-ring.patch
new file mode 100644
index 0000000..d85527f
--- /dev/null
+++ b/1520_fix-race-condition-in-packet-set-ring.patch
@@ -0,0 +1,62 @@
+--- a/net/packet/af_packet.c   2016-12-07 18:10:25.785812861 -0500
++++ b/net/packet/af_packet.c   2016-12-07 18:18:45.597933525 -0500
+@@ -3648,19 +3648,25 @@ packet_setsockopt(struct socket *sock, i
+ 
+               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 *
+       /* 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");
+@@ -4245,8 +4252,6 @@ static int packet_set_ring(struct sock *
+                       goto out;
+       }
+ 
+-      lock_sock(sk);
+-
+       /* Detach socket from network */
+       spin_lock(&po->bind_lock);
+       was_running = po->running;
+@@ -4294,11 +4299,11 @@ static int packet_set_ring(struct sock *
+               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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