4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
The irda_bind() function allocates memory for self->ias_obj without
checking to see if the socket is already bound. A userspace process
could repeatedly bind the socket, have each new object added into the
LM-IAS database, and lose the reference to the old object assigned to
the socket to exhaust memory resources. This patch errors out of the
bind operation when self->ias_obj is already assigned.
CVE-2018-6554
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxx>
Reviewed-by: Seth Arnold <seth.arnold@xxxxxxxxxxxxx>
Reviewed-by: Stefan Bader <stefan.bader@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/irda/af_irda.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -774,6 +774,13 @@ static int irda_bind(struct socket *sock
return -EINVAL;
lock_sock(sk);
+
+ /* Ensure that the socket is not already bound */
+ if (self->ias_obj) {
+ err = -EINVAL;
+ goto out;
+ }
+
#ifdef CONFIG_IRDA_ULTRA
/* Special care for Ultra sockets */
if ((sk->sk_type == SOCK_DGRAM) &&
