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authorMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>2012-07-19 10:13:36 +0400
committerDavid S. Miller <davem@davemloft.net>2012-07-20 22:21:06 +0400
commitb09e786bd1dd66418b69348cb110f3a64764626a (patch)
treee4f12db01edc11d669f32a2d3d6832b22f57f656 /include/linux/net.h
parent521f549097a79dc55e18c3bc752ef2127ad70ac5 (diff)
downloadlinux-b09e786bd1dd66418b69348cb110f3a64764626a.tar.xz
tun: fix a crash bug and a memory leak
This patch fixes a crash tun_chr_close -> netdev_run_todo -> tun_free_netdev -> sk_release_kernel -> sock_release -> iput(SOCK_INODE(sock)) introduced by commit 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d The problem is that this socket is embedded in struct tun_struct, it has no inode, iput is called on invalid inode, which modifies invalid memory and optionally causes a crash. sock_release also decrements sockets_in_use, this causes a bug that "sockets: used" field in /proc/*/net/sockstat keeps on decreasing when creating and closing tun devices. This patch introduces a flag SOCK_EXTERNALLY_ALLOCATED that instructs sock_release to not free the inode and not decrement sockets_in_use, fixing both memory corruption and sockets_in_use underflow. It should be backported to 3.3 an 3.4 stabke. Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: stable@kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/net.h')
-rw-r--r--include/linux/net.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/net.h b/include/linux/net.h
index e9ac2df079ba..dc95700de5df 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -72,6 +72,7 @@ struct net;
#define SOCK_NOSPACE 2
#define SOCK_PASSCRED 3
#define SOCK_PASSSEC 4
+#define SOCK_EXTERNALLY_ALLOCATED 5
#ifndef ARCH_HAS_SOCKET_TYPES
/**