From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794063282; b=eIDCDsL/AUf+/FY4LyirtzxZ7WvmPkhLWL++wYcyMzvaFBRX0hrgF+cQP+0M9k5pI+4g wuj2gjabNLqQVhCChIKk/s2eL2XVhAwdSHqnWAC5HTiiddpVSkdYQwgvGMM4qV1FKwHg2 O++feNIQAo49PgM8m3PFI0t24pCIoeJ++LM798qTVPow56VJz/Nmc6UHaLnzYiivL5pIn WZSSFISgrRKB6gZ9+lXHPDb/bF1MUfv+hHkFEEZXnbTvbXaPkpPJ85SeQLoW8SzZ1YCSg VU9QBkAO6+ui4Bf6wZSOX9fkRreWWW5vksUtcXJtb24EuDdycWXieq/e2RyW+P1nZ3A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063282; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=WJpKPgFfeshsJ0lnO44fSvr39LsbaEp+4yqr1m/EyIU=; b=WAZdR/2o3E48o4gvzht8MsmW+JmPGxT9i8zvnIVF4aQD3dz9SJXsfPM3XSkSx8lGooaj xkpWhqvOSNFaB1PttYO1okXKK+cYSN6symBASKx28TpSPejkUhkIUHnI4M7whCix/46GH 49szRWXhtHZJtTdaB8itGQAUYlCwY0lhnwCZgCbRUZdFcozhPTkR+mgWhRmKN6YVrITw9 ZnNTaWsl5dH6AJpkVEmVtm4Q4L7GBPervHcKW7m0NqmQgK6KUORXU+y0cWVLuTFAPkepZ joLgfsw6UWL+ivMibzGaTz4Q3dwrUnqIpmaL2psTVovs9hZj5bY+mi7c2iN6rail30g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TktNeLGM; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38363606A32D; Sat, 7 Nov 2026 14:54:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TktNeLGM Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAE611F0089F; Sat, 7 Nov 2026 14:54:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063282; bh=WJpKPgFfeshsJ0lnO44fSvr39LsbaEp+4yqr1m/EyIU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TktNeLGMV82sf81IEU59KRk0WD63nNkJ6mW4f8JKW3krdxTgZpP0FW2yXfiVOi9/W GAI9uKCGWO8tPZgRkVtdBgW5QF4LzCAZvxoDijZjy8Y1fIkAB3/Ugey/hH/7GE64BP ib/xj3I0SkvBWojKFaTRITVWrb6YViZY5/6NoZS4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yehyeong Lee , Juergen Gross , Bjorn Helgaas , Sasha Levin Subject: [PATCH 6.18 439/869] xen/pcifront: check that an AER callback exists before calling it Date: Sat, 7 Nov 2026 08:52:01 -0500 Message-ID: <20261107134908.659347229@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yehyeong Lee [ Upstream commit 3b4854b69ee70fffb2fa7acac09e715a7efcbae1 ] pcifront_common_process() handles an AER request from the backend by dispatching on aer_op.cmd to the bound driver's PCI error handler. It only checks that err_handler and err_handler->error_detected are present, then for the mmio_enabled, slot_reset and resume commands it calls the corresponding callback unconditionally. Those three callbacks are optional -- the PCI core NULL-checks each of them individually before use -- and many drivers (for example igb, igc, ice and ixgbevf) install error_detected without all of them. aer_op.cmd comes from the shared ring, so a malicious or buggy backend can send XEN_PCI_OP_aer_mmio (or _slotreset/_resume) for a device whose driver leaves that callback NULL and make the frontend call through a NULL pointer, crashing the guest. Check each callback before calling it. When mmio_enabled or slot_reset is absent, return PCI_ERS_RESULT_RECOVERED so recovery proceeds, as the PCI core does for a missing callback; returning PCI_ERS_RESULT_NONE would instead make xen-pciback tear the guest domain down. Fixes: 956a9202cd12 ("xen-pcifront: Xen PCI frontend driver.") Cc: stable@vger.kernel.org Signed-off-by: Yehyeong Lee Reviewed-by: Juergen Gross Acked-by: Bjorn Helgaas Signed-off-by: Juergen Gross Message-ID: <20261006023443.338194-1-yhlee@isslab.korea.ac.kr> Signed-off-by: Sasha Levin --- drivers/pci/xen-pcifront.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c index 11636634ae512..451476ce10ae9 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -599,11 +599,16 @@ static pci_ers_result_t pcifront_common_process(int cmd, case XEN_PCI_OP_aer_detected: return pdrv->err_handler->error_detected(pcidev, state); case XEN_PCI_OP_aer_mmio: - return pdrv->err_handler->mmio_enabled(pcidev); + if (pdrv->err_handler->mmio_enabled) + return pdrv->err_handler->mmio_enabled(pcidev); + return PCI_ERS_RESULT_RECOVERED; case XEN_PCI_OP_aer_slotreset: - return pdrv->err_handler->slot_reset(pcidev); + if (pdrv->err_handler->slot_reset) + return pdrv->err_handler->slot_reset(pcidev); + return PCI_ERS_RESULT_RECOVERED; case XEN_PCI_OP_aer_resume: - pdrv->err_handler->resume(pcidev); + if (pdrv->err_handler->resume) + pdrv->err_handler->resume(pcidev); return PCI_ERS_RESULT_NONE; default: dev_err(&pdev->xdev->dev, -- 2.53.0