From nobody Fri Nov 14 22:07:09 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 1760502677457740.7799778170576; Tue, 14 Oct 2025 21:31:17 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1v8t5K-00008g-Uq; Wed, 15 Oct 2025 00:25:59 -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 1v8t5J-000089-8i; Wed, 15 Oct 2025 00:25:57 -0400 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1v8t5B-0002kA-JX; Wed, 15 Oct 2025 00:25:57 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 08FB015D9C9; Wed, 15 Oct 2025 07:24:59 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 9B55329FE72; Wed, 15 Oct 2025 07:25:20 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Stefan Hajnoczi , Akihiko Odaki , "Michael S. Tsirkin" , Qing Wang , Michael Tokarev Subject: [Stable-10.1.2 04/11] pcie_sriov: make pcie_sriov_pf_exit() safe on non-SR-IOV devices Date: Wed, 15 Oct 2025 07:25:08 +0300 Message-ID: <20251015042520.68556-4-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.3 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=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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: 1760502679457158500 Content-Type: text/plain; charset="utf-8" From: Stefan Hajnoczi Commit 3f9cfaa92c96 ("virtio-pci: Implement SR-IOV PF") added an unconditional call from virtio_pci_exit() to pcie_sriov_pf_exit(). pcie_sriov_pf_exit() reads from the SR-IOV Capability in Configuration Space: uint8_t *cfg =3D dev->config + dev->exp.sriov_cap; ... unparent_vfs(dev, pci_get_word(cfg + PCI_SRIOV_TOTAL_VF)); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This results in undefined behavior when dev->exp.sriov_cap is 0 because this is not an SR-IOV device. For example, unparent_vfs() segfaults when total_vfs happens to be non-zero. Fix this by returning early from pcie_sriov_pf_exit() when dev->exp.sriov_cap is 0 because this is not an SR-IOV device. Cc: Akihiko Odaki Cc: Michael S. Tsirkin Reported-by: Qing Wang Buglink: https://issues.redhat.com/browse/RHEL-116443 Signed-off-by: Stefan Hajnoczi Reviewed-by: Akihiko Odaki Fixes: cab1398a60eb ("pcie_sriov: Reuse SR-IOV VF device instances") Reviewed-by: Michael S. Tsirkin Message-ID: <20250924155153.579495-1-stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin (cherry picked from commit bab681f752048c3bc22d561b1d314c7ec16419c9) Signed-off-by: Michael Tokarev diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c index 29474d749a..c4f88f0975 100644 --- a/hw/pci/pcie_sriov.c +++ b/hw/pci/pcie_sriov.c @@ -195,7 +195,9 @@ bool pcie_sriov_pf_init(PCIDevice *dev, uint16_t offset, =20 void pcie_sriov_pf_exit(PCIDevice *dev) { - uint8_t *cfg =3D dev->config + dev->exp.sriov_cap; + if (dev->exp.sriov_cap =3D=3D 0) { + return; + } =20 if (dev->exp.sriov_pf.vf_user_created) { uint16_t ven_id =3D pci_get_word(dev->config + PCI_VENDOR_ID); @@ -211,6 +213,8 @@ void pcie_sriov_pf_exit(PCIDevice *dev) pci_config_set_device_id(dev->exp.sriov_pf.vf[i]->config, vf_d= ev_id); } } else { + uint8_t *cfg =3D dev->config + dev->exp.sriov_cap; + unparent_vfs(dev, pci_get_word(cfg + PCI_SRIOV_TOTAL_VF)); } } --=20 2.47.3