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 8CB231F91F6; Tue, 13 Oct 2026 12:35:59 +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=1791894960; cv=none; b=JqjVxm8PNws5WQg3BFzb9Z1Zl7jhWgzWvzIklY2WEnyNrlcCb2ezezPePdJtJCt2UO20Y+Y754GIC1FLlg7DeXDKjqAcCBqBBNVgIJbP8Qs7MgVzDZhp3TkUZ2QFbVPfTEg+879m9aP7WmVnrZZL3X2R5sD2Y1XXfSXCd2spWDE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791894960; c=relaxed/simple; bh=pgm8dVMmQk1Nos7VWm8yUAFd0ETSvvDvIIJTLD2dVT8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DMMvxW4tDs9EE0Yk/lLqcBXLCH43AJXxdd3wIFhY2VXHdqMvnnmZJocyYDlCTYbKZaS86zN029HL6B0Kbe0B44MIdrH9LFyqhtXSUFdAgrFwtF2/8WhfJsMuDOd5nZYaTIEDIma3YVE6hG6VHdLZ5O10QPCqS6ibxStRogThkk4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nMvLPmm6; 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="nMvLPmm6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D28241F000FF; Tue, 13 Oct 2026 12:35:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791894959; bh=x3Co2ZVf3Sjf0XNdj/iwB0czN0+uBpKuS9MsdQAjuds=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nMvLPmm60/zPtCs/9PUjKE7k8IVJHmxJbx2ft7GVRZbLepWQIDzHp+LnY12tQeM+f EtLIK300tU/mg1ryDw9x0xIvowXcWDjDqCUDlw9ci3lPxkC4hma5TaqTfaBciqyc1t iw+XW2A67YZ4e5+j+GrATLzQ+FEPbenbGa5vhBMw= 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 6.12 087/497] net: restrict SO_RESERVE_MEM to TCP sockets and cap max value Date: Tue, 13 Oct 2026 13:34:14 +0200 Message-ID: <20261013112909.953156615@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112907.864180619@linuxfoundation.org> References: <20261013112907.864180619@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 6.12-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 5790d18ef2348..75db38fdfd35f 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1016,7 +1016,7 @@ 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) @@ -1619,7 +1619,7 @@ 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