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authorEric Dumazet <eric.dumazet@gmail.com>2010-11-24 23:11:39 -0500
committerDavid S. Miller <davem@davemloft.net>2010-11-29 12:45:15 -0500
commit25888e30319f8896fc656fc68643e6a078263060 (patch)
treeae484d38b1250da885d3939dd9a97e667fbc871d /net/unix/garbage.c
parent50a4205333c5e545551f1f82b3004ca635407c5c (diff)
af_unix: limit recursion level
Its easy to eat all kernel memory and trigger NMI watchdog, using an exploit program that queues unix sockets on top of others. lkml ref : http://lkml.org/lkml/2010/11/25/8 This mechanism is used in applications, one choice we have is to have a recursion limit. Other limits might be needed as well (if we queue other types of files), since the passfd mechanism is currently limited by socket receive queue sizes only. Add a recursion_level to unix socket, allowing up to 4 levels. Each time we send an unix socket through sendfd mechanism, we copy its recursion level (plus one) to receiver. This recursion level is cleared when socket receive queue is emptied. Reported-by: Марк Коренберг <socketpair@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix/garbage.c')
-rw-r--r--net/unix/garbage.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index 40df93d1cf35..f89f83bf828e 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -96,7 +96,7 @@ static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
96unsigned int unix_tot_inflight; 96unsigned int unix_tot_inflight;
97 97
98 98
99static struct sock *unix_get_socket(struct file *filp) 99struct sock *unix_get_socket(struct file *filp)
100{ 100{
101 struct sock *u_sock = NULL; 101 struct sock *u_sock = NULL;
102 struct inode *inode = filp->f_path.dentry->d_inode; 102 struct inode *inode = filp->f_path.dentry->d_inode;