From: Jason Xing <kernelxing@tencent.com>
Date: Mon, 4 Mar 2024 08:20:36 +0000 (+0800)
Subject: netrom: Fix a data-race around sysctl_netrom_obsolescence_count_initialiser
X-Git-Tag: v5.15.152~55
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b3f0bc3a315cf1af03673a0163c08fe037587acd;p=thirdparty%2Fkernel%2Fstable.git

netrom: Fix a data-race around sysctl_netrom_obsolescence_count_initialiser

[ Upstream commit cfd9f4a740f772298308b2e6070d2c744fb5cf79 ]

We need to protect the reader reading the sysctl value
because the value can be changed concurrently.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 55cd51977fbc2..e5d24462d5100 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -766,7 +766,7 @@ int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
 	if (ax25 != NULL) {
 		ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
 				  ax25->ax25_dev->dev, 0,
-				  sysctl_netrom_obsolescence_count_initialiser);
+				  READ_ONCE(sysctl_netrom_obsolescence_count_initialiser));
 		if (ret)
 			return ret;
 	}