path: root/net/unix/garbage.c
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2010-11-25 04:11:39 +0000
committerDavid S. Miller <davem@davemloft.net>2010-11-29 09:45:15 -0800
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')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index 40df93d1cf3..f89f83bf828 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -96,7 +96,7 @@ static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
unsigned int unix_tot_inflight;
-static struct sock *unix_get_socket(struct file *filp)
+struct sock *unix_get_socket(struct file *filp)
struct sock *u_sock = NULL;
struct inode *inode = filp->f_path.dentry->d_inode;