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=1794049422; b=1pzTT70bvu56nllSlfTjNq0IQeQLa7d+TzxySL+I3jkShs4Dm7TIKctj3CeFrugfkwRH C2dL3FjuIkVr2rJNBuVvHF2g1R/kzaTv8f6ciI3fbbagB1UuAa6vISkgKf6kgxawEo1sL xMbeSqtZa2kDaKwUgCl0tDz50KYOqPsUyhxBVRVIaANhLxjEYpKOKSqhxyM0Uz9szU4Zg sAGJY4q0NVBc5pkH/3PtWVnXkWSrAL8QcL0pfXzHYpoyQtCVxSna2cPT0/n2e4DfaQZoS oR8QtpUC/aNBd6DbZkd6AsCsOhq3/fwjFfL1B+jjYAP8qsUiU90PW/xzwZagybI4RxA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049422; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=yI7KV7TrVLgxtUZTHHnhMEsgtJk8e9TRRyqIq1a05xQ=; b=Sbi8t0YPqIVACsmFBuNpyn2RMscrK4Q3CIAIkiFIdwYBlYvuCvFBFxqWWB7dn0Tdpn1B zclLHL/wnfMvWUbZzI2dx2/gkNAU3Qf9hRaK+QVt6ae61xNZC3K2FJBM8me2QAy+qK4+b ItbsRmnogp+Ky1Q7qPIODS5zc7B/7lhDeikhKINhGAQZJ9sdc6WI7uGysLLz6mCTI4efC 6y4+LhppPo+PuG7MyCFG516HpJZf5NwGBwXciJ1Tzi4JQvGfBuhSpKrEFffs5aIXFaf/e qpxR4AdJZQEqfZhdigHfc7cGUakBKF1mdAsMDAZ0hPXExlE5vNasJ0dBJVGEDkcbXkQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CUqsVNCs; 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 446BF606A332 for ; Sat, 7 Nov 2026 11:03:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CUqsVNCs Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D9531F0089F; Sat, 7 Nov 2026 11:03:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049421; bh=yI7KV7TrVLgxtUZTHHnhMEsgtJk8e9TRRyqIq1a05xQ=; h=From:To:Cc:Subject:Date; b=CUqsVNCsDcbYhTqkW3U23YyTI0br9HAWM7FmFt/lbmDBJw40HbJk1k3Dco418TvQt X2pzdp6BxrbOY1nbIMlZSsSZnIBcSQ5wg1N8il0OoJT/LXGuxjNWqrr9xrWMJCz/iV pftY8TgKO6QlzQq+11r7G/9AOq8dGWH6yBj32iODZ7EtfCWgohlmL6zxe8eI6fnd4t 46QN2dQXsU7yWKqIri4aoyNWPW4RJ5C96po3cHV74DOqiDr8uJ3YADio5sMZXM33/l e0zGKKYAQRzBi9kUmjX7zIWx4BRqyhChvoz+jW2rgeBzjnhvu5/qx/RWjcHfW7YfrZ apDS20bxRKMbQ== From: Sasha Levin To: yhlee@isslab.korea.ac.kr, jgross@suse.com, bhelgaas@google.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] xen/pcifront: check that an AER callback exists before calling it" failed to apply to 5.15-stable tree Date: Sat, 7 Nov 2026 06:03:40 -0500 Message-ID: <20261107060339-failed-5.15-3b4854b69ee7@kernel.org> X-Mailer: git-send-email 2.53.0 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 3b4854b69ee70fffb2fa7acac09e715a7efcbae1 # git commit -s git send-email --to '' --in-reply-to '20261107060339-failed-5.15-3b4854b69ee7@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 3b4854b69ee70fffb2fa7acac09e715a7efcbae1 Mon Sep 17 00:00:00 2001 From: Yehyeong Lee Date: Tue, 6 Oct 2026 11:34:43 +0900 Subject: [PATCH] xen/pcifront: check that an AER callback exists before calling it 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> --- 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 0dea8a69fa36c..b8f2921cc253f 100644 --- a/drivers/pci/xen-pcifront.c +++ b/drivers/pci/xen-pcifront.c @@ -598,11 +598,16 @@ 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