diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-11-25 04:11:39 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-11-29 09:45:15 -0800 |
| commit | 25888e30319f8896fc656fc68643e6a078263060 (patch) | |
| tree | ae484d38b1250da885d3939dd9a97e667fbc871d /net/unix/garbage.c | |
| parent | 50a4205333c5e545551f1f82b3004ca635407c5c (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.c | 2 |
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); 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; |