From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C715C83F1F for ; Mon, 28 Aug 2023 10:38:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231723AbjH1Kh5 (ORCPT ); Mon, 28 Aug 2023 06:37:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231682AbjH1Khk (ORCPT ); Mon, 28 Aug 2023 06:37:40 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FAE2B9 for ; Mon, 28 Aug 2023 03:37:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 97C6763F26 for ; Mon, 28 Aug 2023 10:37:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A21D0C433C7; Mon, 28 Aug 2023 10:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693219057; bh=/5KcCZGeWRu/1Z8vHb2hwiN0mY7PcpAfrP5x97pC/OU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0TxDa2tBG7WwDLuV4cUuZwe4snNmX4WL9wr5Gjzi1TVswog9EddNsey5lGaqzkR0l gl6F6l+fKonYtZl9ERaclYliSBWa5CxCyoQGYALCcF1D+/aRTsCXQ6i+tUm4Yk1oYe oX7eiQFCTIlg/990+AbyA3aclkMKQ3rKzRIxRxKg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nathan Lynch , Kees Cook , Michael Ellerman Subject: [PATCH 5.4 057/158] powerpc/rtas_flash: allow user copy to flash block cache objects Date: Mon, 28 Aug 2023 12:12:34 +0200 Message-ID: <20230828101159.235015468@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101157.322319621@linuxfoundation.org> References: <20230828101157.322319621@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nathan Lynch commit 4f3175979e62de3b929bfa54a0db4b87d36257a7 upstream. With hardened usercopy enabled (CONFIG_HARDENED_USERCOPY=y), using the /proc/powerpc/rtas/firmware_update interface to prepare a system firmware update yields a BUG(): kernel BUG at mm/usercopy.c:102! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 2232 Comm: dd Not tainted 6.5.0-rc3+ #2 Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 of:IBM,FW860.50 (SV860_146) hv:phyp pSeries NIP: c0000000005991d0 LR: c0000000005991cc CTR: 0000000000000000 REGS: c0000000148c76a0 TRAP: 0700 Not tainted (6.5.0-rc3+) MSR: 8000000000029033 CR: 24002242 XER: 0000000c CFAR: c0000000001fbd34 IRQMASK: 0 [ ... GPRs omitted ... ] NIP usercopy_abort+0xa0/0xb0 LR usercopy_abort+0x9c/0xb0 Call Trace: usercopy_abort+0x9c/0xb0 (unreliable) __check_heap_object+0x1b4/0x1d0 __check_object_size+0x2d0/0x380 rtas_flash_write+0xe4/0x250 proc_reg_write+0xfc/0x160 vfs_write+0xfc/0x4e0 ksys_write+0x90/0x160 system_call_exception+0x178/0x320 system_call_common+0x160/0x2c4 The blocks of the firmware image are copied directly from user memory to objects allocated from flash_block_cache, so flash_block_cache must be created using kmem_cache_create_usercopy() to mark it safe for user access. Fixes: 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0") Signed-off-by: Nathan Lynch Reviewed-by: Kees Cook [mpe: Trim and indent oops] Signed-off-by: Michael Ellerman Link: https://msgid.link/20230810-rtas-flash-vs-hardened-usercopy-v2-1-dcf63793a938@linux.ibm.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/rtas_flash.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/arch/powerpc/kernel/rtas_flash.c +++ b/arch/powerpc/kernel/rtas_flash.c @@ -710,9 +710,9 @@ static int __init rtas_flash_init(void) if (!rtas_validate_flash_data.buf) return -ENOMEM; - flash_block_cache = kmem_cache_create("rtas_flash_cache", - RTAS_BLK_SIZE, RTAS_BLK_SIZE, 0, - NULL); + flash_block_cache = kmem_cache_create_usercopy("rtas_flash_cache", + RTAS_BLK_SIZE, RTAS_BLK_SIZE, + 0, 0, RTAS_BLK_SIZE, NULL); if (!flash_block_cache) { printk(KERN_ERR "%s: failed to create block cache\n", __func__);