From nobody Thu Oct 9 16:36:51 2025 Received: from NAM10-DM6-obe.outbound.protection.outlook.com (mail-dm6nam10on2054.outbound.protection.outlook.com [40.107.93.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69B555383; Mon, 16 Jun 2025 21:51:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.93.54 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750110663; cv=fail; b=njkxtaJ1z7CuocN6uLpsXZAd8cQPDa2OKreXm3SJN36JGWSS7EdaAy3Vh+tCuZXkve0+2eJMVRGHidhR1ly2hNyDmDorKFzzgIabfd7fuordkfI4/8laUDf4he2YFvLx6LEhM88Ys+XosmCmUwHnSxSbHG2DluDZtsolXj8N0mY= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750110663; c=relaxed/simple; bh=he3OyxiBjC3Vn0gi2AVj3z8c9PfQerR07/CirYU5jM0=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=R1cPAcI56ZCDk8tK9fZlsaIZi/NlzOCRtBkTtBvRQaXTsKxl14JS14ybYcVVMh9kp7CGYvuJr8um2P2UVl9iNrsOxX6KS1Ph2k0xblevmFdQdyt9zgnb/owP4S8ZuPPsu4mYm+UXbQX+Rit7Jc1shH/OdEYl8qGQB1BkpmFqdwc= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=LbS+ePmw; arc=fail smtp.client-ip=40.107.93.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="LbS+ePmw" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=annZ9QHYI7yWLY4qRdLmkWwoZQC10C2Llx/CUorGZmmYJ42MQESOQEPlbJ0AE9gDMgMs2QQ/18hVJFE5i1GG0mPkxvoHSAzoUOzdvNg9E+kUro7Pis1bGAo1LfselbMLYSWVA6Uz/N62LIJ3ErApVu+4owrMjfoNObWy45okuGVxy9kSfiBilpNQJZwE0VtHugnf4S2F4hROx5mH4T8E4HZPqyP1d4Ohcq8wOTNQzAoGy8BY+yui6rtZuQwfz4xrSwHIu32Bo8OKrQNHKcCjC1V8aYvrUR6RR9aRLvJdP59UY01CHa1G5mL+CZKGWBANVsyIkLohXQ+Ju46erRSu2g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=7xJLt1qnW3D8r2S5TxL5ehkEX6NMByn66ChfX/Jl0vQ=; b=JIjB75VIDBh49ngHThrze7sKmGAfL1oOBIB99DCeRa5eg7TFUUCxsLNJXRrhGyz1C13YsPIMVf1hMZwp7jQYSIowD3pJoEOnja51RqTevEEMfWF0WOcRL8OWrnE0hXk/3fJd07WSpCPECR9AlkL69I3GqSlnWuGJJl7BXeZxtGgP4Pe5O+vJRcPLJXCvjuSWjziKXz00h11NzPBhHj/X6b6huFk/LOb65PEmmwc2lzYZH+0aLZsmyJMVGvGfYYOwAQKuwAeO14OrkrIKvCdzAx9sau8wPSzK+JBsRkA0J1gDoKffin/topQeqBuCkWETexZpGWBjBKHD9AOk8ipLSg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=gondor.apana.org.au smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=7xJLt1qnW3D8r2S5TxL5ehkEX6NMByn66ChfX/Jl0vQ=; b=LbS+ePmwS1SxM0Uo623p5gBIAuCP3etoNiRwa/PIbpcK9Fjd2z+TSxLdYCFqLQiM5zUvBEtERqGWnMUBV0pEFASzDQ2SXwr2KBOBdcyeKiAt+fh7DDnxy/IHpgdr0Wbu8n8vaBvhlp+E6cbV3ZzMvLIk+OsHyPazgwJfttJRxak= Received: from MW4PR03CA0192.namprd03.prod.outlook.com (2603:10b6:303:b8::17) by BL4PR12MB9721.namprd12.prod.outlook.com (2603:10b6:208:4ed::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8835.28; Mon, 16 Jun 2025 21:50:55 +0000 Received: from SJ5PEPF00000208.namprd05.prod.outlook.com (2603:10b6:303:b8:cafe::34) by MW4PR03CA0192.outlook.office365.com (2603:10b6:303:b8::17) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8835.19 via Frontend Transport; Mon, 16 Jun 2025 21:50:55 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by SJ5PEPF00000208.mail.protection.outlook.com (10.167.244.41) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8835.15 via Frontend Transport; Mon, 16 Jun 2025 21:50:54 +0000 Received: from ethanolx7e2ehost.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 16 Jun 2025 16:50:53 -0500 From: Ashish Kalra To: , , , CC: , , , , , Subject: [RESEND PATCH v3] crypto: ccp: Fix SNP panic notifier unregistration Date: Mon, 16 Jun 2025 21:50:27 +0000 Message-ID: <20250616215027.68768-1-Ashish.Kalra@amd.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ5PEPF00000208:EE_|BL4PR12MB9721:EE_ X-MS-Office365-Filtering-Correlation-Id: 974e4f8d-96b1-4126-745b-08ddad1fdeba X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|82310400026|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?TxZZPdljW7cAaR7z/Xj0UI7qSzLZc8Z9Heww3zIcyAGDMvV5eOyFGtoIP6nx?= =?us-ascii?Q?PQZ16dIYJmfI7pGFMYhQjVJPsto3TY5hvaHsG5TxIQSXOl/+rF1fh3sM2iiR?= =?us-ascii?Q?Uf7YcwLtmx/eRAugCQui5DQow9BmssltzJoFlpEfdS+cz28zz3YOv53HGQsR?= =?us-ascii?Q?dG7Xum5NZg28mSA8f26VmR1HNoedKKOy+2SvCRlCb/JvMZIsSoPC0yTv4RPC?= =?us-ascii?Q?hopvhuociNyYDRZXB6DcfR+b7w7PGSYt+68wIb5dEDXdrRFsjnCZ8zktHkaN?= =?us-ascii?Q?7EvYkIkzrSu0hfQT8dzW7hBOt3XZhmeg6rI1Le+MDH0wB80eDebnHOxNA/YC?= =?us-ascii?Q?aGmh2xfYowXvrYaG+EsJUNY+6KOg6SgNyVUAr1aeCwV+TupkxIuqMyD/18oo?= =?us-ascii?Q?fV3BZsFcgxtFODOtZXX7xlnK5eXH4RZgGI4jqyG/S7DWVD+Er0KluziQ58bF?= =?us-ascii?Q?LRjB2SaVVGOiFu9CVww7ng4wnyx7aEuqBGQsHMiaTNuqBYxtD6REDd0KLogz?= =?us-ascii?Q?42k2Ll0EuPF7XphyV24ydY1m6tWXtwhkVcD6OeNhM/os/1k3/gmV/bUOJlQV?= =?us-ascii?Q?zJCxVMan3rzahGtV5/IAdmlKcdLAa+uL/2gDv7KqPp8iWtACx+Q0inTMm//b?= =?us-ascii?Q?McawPxYjULQkn/k6DP3/GXw/OVmgIdIRqn4YQTLCIb8XkeWQXCPou7KUxBmS?= =?us-ascii?Q?usT41AO4BPg+Kru2hxqg0viOf3JqlTayZug/0KDyMWgF+/dJjtxaFDORxHo+?= =?us-ascii?Q?4mAvvLmBOsDNShZEmWb1JETLRVBv2crQnsYwIl+M3unboS8dSjqr2MjxiDcm?= =?us-ascii?Q?2ZA67FYixzzLSqhxbD0bG7y0peONhlCTLLj2JJNhlRQUZV7HLO9vlJqhd0k7?= =?us-ascii?Q?WvFa4cLmylDZecFf6D95M4Eq1olybLphiZ/vxPFvbgAXu2Q8tXsGceZkhpC/?= =?us-ascii?Q?1H+XyUp1YEeLmVfD8oMxpgl/n3FROF6SE9pkl4VvSSJnGhBLPco1pOAsn3B1?= =?us-ascii?Q?GtWbfLbe3hVf3TBRwZLD6WS/4bGgJSuidKxA+3MtTwLXMF8vaWOWQJBPFs7U?= =?us-ascii?Q?m/4fSxFdQ6YR4qn3kHvre2SouMcziSwCn8BvN5WkIX0FW6iqhBNxUMzEzIXg?= =?us-ascii?Q?wz+gYQ8Dshsg+xkliVS4KOTnow8VJwSUWn80iLaOaYzW7pgDr6OyHIhXIKEw?= =?us-ascii?Q?k7RIKhcNDWvoKZnzwMNMprbGjMRm78MYvMQhCcGTTaWqG3qVoScyn9sqYKVD?= =?us-ascii?Q?iel5Oj+yrsakYEjqEGHXXbS82qv/BSCieW6rtdX9uL0X8wgl2CK994aRiSuX?= =?us-ascii?Q?qcZokOxHeiXKktTSXoFxDwZfU2cYsWA4KB6dhqUGuhLPcfK+D6ECEIU5s1Rb?= =?us-ascii?Q?OgAoJSTgt10hMEhRjk/YnLsvpCEXzz/sSY5rnlR+XkBGTOWEvXxoBklgsMsw?= =?us-ascii?Q?p/q2+V1seGkl1XdHcgmW/bZraE8rq3ouas1lf4+2Pa5LXWtcDiUaiLTAO4OJ?= =?us-ascii?Q?rW1dU/jh4yiueRMXylCpR7xbXnqwq4dRaOex?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(82310400026)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Jun 2025 21:50:54.7381 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 974e4f8d-96b1-4126-745b-08ddad1fdeba X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SJ5PEPF00000208.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL4PR12MB9721 Content-Type: text/plain; charset="utf-8" From: Ashish Kalra Panic notifiers are invoked with RCU read lock held and when the SNP panic notifier tries to unregister itself from the panic notifier callback itself it causes a deadlock as notifier unregistration does RCU synchronization. Code flow for SNP panic notifier: snp_shutdown_on_panic() -> __sev_firmware_shutdown() -> __sev_snp_shutdown_locked() -> atomic_notifier_chain_unregister(.., &snp_panic_notifier) Fix SNP panic notifier to unregister itself during SNP shutdown only if panic is not in progress. Reviewed-by: Tom Lendacky Cc: stable@vger.kernel.org Fixes: 19860c3274fb ("crypto: ccp - Register SNP panic notifier only if SNP= is enabled") Signed-off-by: Ashish Kalra --- drivers/crypto/ccp/sev-dev.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 8fb94c5f006a..17edc6bf5622 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1787,8 +1787,14 @@ static int __sev_snp_shutdown_locked(int *error, boo= l panic) sev->snp_initialized =3D false; dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n"); =20 - atomic_notifier_chain_unregister(&panic_notifier_list, - &snp_panic_notifier); + /* + * __sev_snp_shutdown_locked() deadlocks when it tries to unregister + * itself during panic as the panic notifier is called with RCU read + * lock held and notifier unregistration does RCU synchronization. + */ + if (!panic) + atomic_notifier_chain_unregister(&panic_notifier_list, + &snp_panic_notifier); =20 /* Reset TMR size back to default */ sev_es_tmr_size =3D SEV_TMR_SIZE; --=20 2.34.1