From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E6A524E535E; Fri, 9 Oct 2026 14:21:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791555712; cv=none; b=Gx4s3WVNvmPXe/AFH1qZ3H90fz/YHZHqoYW3eaLAJPemQ8uRlvWisuhIfBSBBSnGY0/k8MFT9zy0+apG9SGkZ0Wp9Uz8w/CSMdVvbxkKuHCRsRcFEUAnECSs9MSNWu+DcOmCrSd18HJep4S1BARVuZQOZDJmSmLxqC+8WU8skFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791555712; c=relaxed/simple; bh=qNrIExy3zpYyc5DzShk09Gpq4tJx66jmUulOBzEGOmA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pUAdjzywW3NRAebz4nz60RfveYbetu9OMYTIwc1KlwAVVmEVNSd0hsar/HwGrmeb8v/VcgLH5ZsAPp563Y99+zZVMxGvt1g2fw3v458+bGbXdRtoICnOp4IQlypxeWAceRYW7PUWjUFbkj99sq5Zo4sKo1Fa++x59dk+dj84g68= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JwKHE1ut; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JwKHE1ut" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10E8A1F00893; Fri, 9 Oct 2026 14:21:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791555710; bh=wBijhZ/Ir5W3yTNOQEvov+IIAkK6TfNKM0RmmY7LN24=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=JwKHE1utcjM2Pn8qF9qQPLc2V6rAMBH8GKO+ufszdkl933Dy5U1cvZXSDRCLPXSXT opoa9EV638yLi8VNP5fGgE55ZYfFyENCc7wQn2Tw+CV0ApizbpqQNJpy1HGn2KH6lE aIamif76oaVFmyxpSyuIQdyRv9T6ZIHrAWg+8H8o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Cai Xinchen , Eric Dumazet , Wei Wang , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 103/403] net: restrict SO_RESERVE_MEM to TCP sockets and cap max value Date: Fri, 9 Oct 2026 16:07:44 +0200 Message-ID: <20261009140954.494440595@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261009140952.119038291@linuxfoundation.org> References: <20261009140952.119038291@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 37e02c42a00be692c06343e11779aadc45f45971 ] Commit 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM") and commit d00c8ee31729 ("net: fix possible NULL deref in sock_reserve_memory") only checked sk_has_account(sk), which is true for both TCP and UDP sockets. However, SO_RESERVE_MEM and sk_unused_reserved_mem() are currently only supported by TCP: - On UDP sockets, sk->sk_forward_alloc is protected by sk->sk_receive_queue.lock, whereas sock_reserve_memory() and sock_release_reserved_memory() only acquire lock_sock(sk). Concurrent UDP packet reception/release and setsockopt(SO_RESERVE_MEM) corrupt sk_forward_alloc and memcg accounting. - udp_rmem_release() reclaims excess sk_forward_alloc without accounting for sk_unused_reserved_mem(sk). Restrict sock_reserve_memory() to TCP sockets (sk_is_tcp(sk)) for now. Supporting SO_RESERVE_MEM for UDP (acquiring sk_receive_queue.lock and honoring sk_unused_reserved_mem() in udp_rmem_release()) can be done in a future net-next series if needed. In addition, reject val > SZ_1G with -EINVAL in sk_setsockopt(SO_RESERVE_MEM). Without an upper bound, values near INT_MAX cause sk_mem_pages(delta) and (pages << PAGE_SHIFT) to overflow 32-bit signed int, corrupting sk->sk_forward_alloc and sk->sk_reserved_mem. Using a page-aligned cap (SZ_1G) ensures that the page-rounded sk->sk_reserved_mem reported by getsockopt(SO_RESERVE_MEM) can always be passed back to setsockopt(SO_RESERVE_MEM). Fixes: 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM") Reported-by: Cai Xinchen Closes: https://lore.kernel.org/netdev/5a88421d-10ef-4fca-9acb-85a27a3c1173@huawei.com/ Signed-off-by: Eric Dumazet Reviewed-by: Wei Wang Link: https://patch.msgid.link/20260925135244.3715196-2-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 0d5f167e6ce69..9031349d08c21 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1024,7 +1024,7 @@ static int sock_reserve_memory(struct sock *sk, int bytes) bool charged; int pages; - if (!mem_cgroup_sk_enabled(sk) || !sk_has_account(sk)) + if (!mem_cgroup_sk_enabled(sk) || !sk_is_tcp(sk)) return -EOPNOTSUPP; if (!bytes) @@ -1645,7 +1645,7 @@ int sk_setsockopt(struct sock *sk, int level, int optname, { int delta; - if (val < 0) { + if (val < 0 || val > SZ_1G) { ret = -EINVAL; break; } -- 2.53.0