From nobody Fri Apr 4 06:30:30 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1742019637820525.328165476362; Fri, 14 Mar 2025 23:20:37 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ttKre-0003SU-Cq; Sat, 15 Mar 2025 02:19:20 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ttKrL-0003EZ-UP; Sat, 15 Mar 2025 02:19:00 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ttKrH-0003GT-QW; Sat, 15 Mar 2025 02:18:59 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 8C1A9FF9D6; Sat, 15 Mar 2025 09:17:07 +0300 (MSK) Received: from gandalf.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 6377D1CAC3F; Sat, 15 Mar 2025 09:18:01 +0300 (MSK) Received: by gandalf.tls.msk.ru (Postfix, from userid 1000) id 43174558C3; Sat, 15 Mar 2025 09:18:01 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Akihiko Odaki , "Michael S . Tsirkin" , Michael Tokarev Subject: [Stable-9.2.3 10/51] hw/net: Fix NULL dereference with software RSS Date: Sat, 15 Mar 2025 09:17:16 +0300 Message-Id: <20250315061801.622606-10-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1742019638458019000 Content-Type: text/plain; charset="utf-8" From: Akihiko Odaki When an eBPF program cannot be attached, virtio_net_load_ebpf() returns false, and virtio_net_device_realize() enters the code path to handle errors because of this, but it causes NULL dereference because no error is generated. Change virtio_net_load_ebpf() to return false only when a fatal error occurred. Fixes: b5900dff14e5 ("hw/net: report errors from failing to use eBPF RSS FD= s") Signed-off-by: Akihiko Odaki Message-Id: <20250116-software-v1-1-9e5161b534d8@daynix.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit bc82af6b0dcb0933e72640851fdd2594f822b23e) Signed-off-by: Michael Tokarev diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 6e8c51a2db..f8c6ccbec4 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1352,18 +1352,25 @@ exit: =20 static bool virtio_net_load_ebpf(VirtIONet *n, Error **errp) { - bool ret =3D false; + if (!virtio_net_attach_ebpf_to_backend(n->nic, -1)) { + return true; + } =20 - if (virtio_net_attach_ebpf_to_backend(n->nic, -1)) { - trace_virtio_net_rss_load(n, n->nr_ebpf_rss_fds, n->ebpf_rss_fds); - if (n->ebpf_rss_fds) { - ret =3D virtio_net_load_ebpf_fds(n, errp); - } else { - ret =3D ebpf_rss_load(&n->ebpf_rss, errp); - } + trace_virtio_net_rss_load(n, n->nr_ebpf_rss_fds, n->ebpf_rss_fds); + + /* + * If user explicitly gave QEMU RSS FDs to use, then + * failing to use them must be considered a fatal + * error. If no RSS FDs were provided, QEMU is trying + * eBPF on a "best effort" basis only, so report a + * warning and allow fallback to software RSS. + */ + if (n->ebpf_rss_fds) { + return virtio_net_load_ebpf_fds(n, errp); } =20 - return ret; + ebpf_rss_load(&n->ebpf_rss, &error_warn); + return true; } =20 static void virtio_net_unload_ebpf(VirtIONet *n) @@ -3801,23 +3808,7 @@ static void virtio_net_device_realize(DeviceState *d= ev, Error **errp) net_rx_pkt_init(&n->rx_pkt); =20 if (virtio_has_feature(n->host_features, VIRTIO_NET_F_RSS)) { - Error *err =3D NULL; - if (!virtio_net_load_ebpf(n, &err)) { - /* - * If user explicitly gave QEMU RSS FDs to use, then - * failing to use them must be considered a fatal - * error. If no RSS FDs were provided, QEMU is trying - * eBPF on a "best effort" basis only, so report a - * warning and allow fallback to software RSS. - */ - if (n->ebpf_rss_fds) { - error_propagate(errp, err); - } else { - warn_report("unable to load eBPF RSS: %s", - error_get_pretty(err)); - error_free(err); - } - } + virtio_net_load_ebpf(n, errp); } } =20 --=20 2.39.5