This is a note to let you know that I've just added the patch titled
net: annotate data-races around sk->sk_reserved_mem
to the 6.1-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-annotate-data-races-around-sk-sk_reserved_mem.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d1ee12009f4b548a460068a526403dfdd7fbf7ff
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri Jul 28 15:03:08 2023 +0000
net: annotate data-races around sk->sk_reserved_mem
[ Upstream commit fe11fdcb4207907d80cda2e73777465d68131e66 ]
sk_getsockopt() runs locklessly. This means sk->sk_reserved_mem
can be read while other threads are changing its value.
Add missing annotations where they are needed.
Fixes: 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Wei Wang <weiwan@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/core/sock.c b/net/core/sock.c
index 0c1baa5517f11..9483820833c5b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -996,7 +996,7 @@ static void sock_release_reserved_memory(struct sock *sk, int bytes)
bytes = round_down(bytes, PAGE_SIZE);
WARN_ON(bytes > sk->sk_reserved_mem);
- sk->sk_reserved_mem -= bytes;
+ WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
sk_mem_reclaim(sk);
}
@@ -1033,7 +1033,8 @@ static int sock_reserve_memory(struct sock *sk, int bytes)
}
sk->sk_forward_alloc += pages << PAGE_SHIFT;
- sk->sk_reserved_mem += pages << PAGE_SHIFT;
+ WRITE_ONCE(sk->sk_reserved_mem,
+ sk->sk_reserved_mem + (pages << PAGE_SHIFT));
return 0;
}
@@ -1922,7 +1923,7 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
break;
case SO_RESERVE_MEM:
- v.val = sk->sk_reserved_mem;
+ v.val = READ_ONCE(sk->sk_reserved_mem);
break;
case SO_TXREHASH:
