This is a note to let you know that I've just added the patch titled
net: Fix data-races around sysctl_mem.
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:
net-fix-data-races-around-sysctl_mem.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 c8f2e02504f1dae63337469796f48c9673db0621
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 6 16:40:00 2022 -0700
net: Fix data-races around sysctl_mem.
[ Upstream commit 310731e2f1611d1d13aae237abcf8e66d33345d5 ]
While reading .sysctl_mem, it can be changed concurrently.
So, we need to add READ_ONCE() to avoid data-races.
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/include/net/sock.h b/include/net/sock.h
index 3c4fb8f03fd9..6bef0ffb1e7b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1534,7 +1534,7 @@ void __sk_mem_reclaim(struct sock *sk, int amount);
/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
static inline long sk_prot_mem_limits(const struct sock *sk, int index)
{
- long val = sk->sk_prot->sysctl_mem[index];
+ long val = READ_ONCE(sk->sk_prot->sysctl_mem[index]);
#if PAGE_SIZE > SK_MEM_QUANTUM
val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
