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=1794064575; b=dymt6M2lrEwTiAaGxQmRsxorRdidt6ehNcRbpRD8U3I1rMlfzFkXM2/b+cG622QNWeuM QbovPhhsua9g0/Dh2seYDz7ApjwZL4KGwSajCG2kj2L67o4Y5KxND1WX/tjqi87ky1109 eu0IcVuSJuglRb6g9crwJZAU2+RWcsInyvHM1swijjDjLMaD17RUA1i9IeSlYFwUtQ4TJ cNIpbyOZY+EbeDodi5Ylod80Nno8EcYCaZjRakqGx8+jsRY0BmyL/ZVfl/DPyEDU4I6XJ CTOZdYSqYkcZc+4rFmp+5KAzjuRjcjbEOAx11/7sT3FwfYMuXUHTa3UbYPnr09T/xvQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794064575; 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=WZCC3IW8jgjpIxJImnJuqa/5YRqIK8epkPgtXH/ymQk=; b=oGCyWdS8JsgPWM5UB3criOoJNND5d3kSpxFDrFV2jQYKHzBGcJsqw8hhh41TH5XKHg30 9RV3bdK9ZaB48SdF5NMLkXYCeXxzS5rzZrbgsrKTjGb48vnUp3BRbnCLorB7Pzf4qm3A7 sWzDGxuMwlc2TpyghOoUsE5s+bkN934c/gbMrmYHEt8gkz1Ol4aGHc2okOmkO/cIJkxVg wnEtSisK1dfaF0ojlN+jaXIE9HD3qFsaL7IHW11Ny982caadWFNMfFc/fw7vw7TmZuRJf ntsBv0v8iLnGJGunM7BfFXJ6jkyyd+ljwmEDl8gFgBKttZhwFTpzhuvY7cmy1WAgOrg== 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=IgImsAHw; 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 63368606D809; Sat, 7 Nov 2026 15:16:15 +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=IgImsAHw Received: by smtp.kernel.org (Postfix) with ESMTPSA id F16851F0089F; Sat, 7 Nov 2026 15:16:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794064575; bh=WZCC3IW8jgjpIxJImnJuqa/5YRqIK8epkPgtXH/ymQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IgImsAHwpgPGp8A33GGqutnbYgCGurqaL+YxXKfcY6eG28xgt37ufHlniDGUZ20OT bl+UgHylGfoMk+Cz2sRgac06ttOyR16PaP8Jb0ZQB3qCmfXsOilcjVCGjmwtZypwUj /fkmDXTYMlBIyPT3arWyXP34nsqWheuMfTFKMmdQ= 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 7.3 0595/1257] xen/pcifront: check that an AER callback exists before calling it Date: Sat, 7 Nov 2026 08:48:11 -0500 Message-ID: <20261107134955.761540671@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@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 7.3-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 cffc32d660327..5c6f7796d204a 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