Commit:     284b327be2f86cf751316ff344b6945e580e654f
Parent:     5c80f1ae9842a8b7985acd0f02efb9828effb05f
Author:     Pavel Emelyanov <[EMAIL PROTECTED]>
AuthorDate: Sat Nov 10 22:08:30 2007 -0800
Committer:  David S. Miller <[EMAIL PROTECTED]>
CommitDate: Sat Nov 10 22:08:30 2007 -0800

    [UNIX]: The unix_nr_socks limit can be exceeded
    The unix_nr_socks value is limited with the 2 * get_max_files() value,
    as seen from the unix_create1(). However, the check and the actual
    increment are separated with the GFP_KERNEL allocation, so this limit
    can be exceeded under a memory pressure - task may go to sleep freeing
    the pages and some other task will be allowed to allocate a new sock
    and so on and so forth.
    So make the increment before the check (similar thing is done in the
    sock_kmalloc) and go to kmalloc after this.
    Signed-off-by: Pavel Emelyanov <[EMAIL PROTECTED]>
    Signed-off-by: David S. Miller <[EMAIL PROTECTED]>
 net/unix/af_unix.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ab9048a..e835da8 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -599,15 +599,14 @@ static struct sock * unix_create1(struct net *net, struct 
socket *sock)
        struct sock *sk = NULL;
        struct unix_sock *u;
-       if (atomic_read(&unix_nr_socks) >= 2*get_max_files())
+       atomic_inc(&unix_nr_socks);
+       if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;
        sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
        if (!sk)
                goto out;
-       atomic_inc(&unix_nr_socks);
@@ -625,6 +624,8 @@ static struct sock * unix_create1(struct net *net, struct 
socket *sock)
        unix_insert_socket(unix_sockets_unbound, sk);
+       if (sk == NULL)
+               atomic_dec(&unix_nr_socks);
        return sk;
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