From: Eric Dumazet <edumazet@xxxxxxxxxx> [ 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> --- net/core/sock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) 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: -- 2.40.1