From 764f4eb6846f5475f1244767d24d25dd86528a4a Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 22 Mar 2022 17:41:47 -0700
Subject: [PATCH] llc: fix netdevice reference leaks in llc_ui_bind()
Patch-mainline: v5.18-rc1
Git-commit: 764f4eb6846f5475f1244767d24d25dd86528a4a
References: CVE-2022-28356 bsc#1197391
Whenever llc_ui_bind() and/or llc_ui_autobind()
took a reference on a netdevice but subsequently fail,
they must properly release their reference
or risk the infamous message from unregister_netdevice()
at device dismantle.
unregister_netdevice: waiting for eth0 to become free. Usage count = 3
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: 赵子轩 <beraphin@gmail.com>
Reported-by: Stoyan Manolov <smanolov@suse.de>
Link: https://lore.kernel.org/r/20220323004147.1990845-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Denis Kirjanov <dkirjanov@suse.de>
---
net/llc/af_llc.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 26c00ebf4fba..c86256064743 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -311,6 +311,10 @@ static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out:
+ if (rc) {
+ dev_put(llc->dev);
+ llc->dev = NULL;
+ }
return rc;
}
@@ -408,6 +412,10 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
out_put:
llc_sap_put(sap);
out:
+ if (rc) {
+ dev_put(llc->dev);
+ llc->dev = NULL;
+ }
release_sock(sk);
return rc;
}
--
2.16.4