This is a note to let you know that I've just added the patch titled
tcp: Fix a data-race around sysctl_tcp_max_orphans.
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-fix-a-data-race-around-sysctl_tcp_max_orphans.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a18e58594b70f96a4354decdec374e052926f387
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 6 16:39:58 2022 -0700
tcp: Fix a data-race around sysctl_tcp_max_orphans.
[ Upstream commit 47e6ab24e8c6e3ca10ceb5835413f401f90de4bf ]
While reading sysctl_tcp_max_orphans, it can be changed concurrently.
So, we need to add READ_ONCE() to avoid a data-race.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e31cf137c614..f2fd1779d925 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2735,7 +2735,8 @@ static void tcp_orphan_update(struct timer_list *unused)
static bool tcp_too_many_orphans(int shift)
{
- return READ_ONCE(tcp_orphan_cache) << shift > sysctl_tcp_max_orphans;
+ return READ_ONCE(tcp_orphan_cache) << shift >
+ READ_ONCE(sysctl_tcp_max_orphans);
}
bool tcp_check_oom(struct sock *sk, int shift)
