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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3233710BA424 for ; Sat, 28 Mar 2026 07:41:51 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fjTwT4Mdnz2yr8; Sat, 28 Mar 2026 18:41:29 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=113.46.200.222 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774683689; cv=none; b=Y5oGqnRNUzVqDpw3lDfM25sTKGX8Zv5R23J5/6hdGiLwKW0zjpKfeGM6E1w9J3JN8J3kDPFGxky8JcJa2al7q70SbQA3+ITAJIHPiCXuVKKbIVVFT+195UjGO0HFEfycaylWDxdT7sSTnmxBRxsbv1oxXv9lCaA1yZsEAoSZjVrsN+qKqjQLdu1H/VncuiYbB4cK3LD6+vqL4Wwx3d/MKwPaW2GB5FtQ1iY7UKDTciuxv/T7PAQNzlj5a9FvRiZBF2x9IvKymQdgYf3I6iKCDqsvpkYhUrNsYbCgYF0VEzHMEhvKxYxJbZDSSITezEC5FEtbtzpasDMKWda253gkFQ== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1774683689; c=relaxed/relaxed; bh=7Ej/nGP6D4OZlN2NP0wOiKbhFa+CLfU7f01IuTLoNYc=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VlfsPUl4X09AhW07y5gi1nVyhTD5xTuNa7+tNKeY4ansRTYgjOi8OUD91HdtNIS1X5bSPi8WqlDS8k25z9YbmW6koy5u1QdfrEqrhfXVlbVFVw9skQBxdsuy7aKXu622IXPrkWDcAOhxvc9Z+ZdsQfYwkgSRJSxxX42BLWJJlRBUBsJdJ7YVz6762TYK4v2/lwmpJ2HwnupQbjQ1friiJ6MKe7+Bp1gsYGK80AVmHsdqKMF4s7vgo9GjCIE9H5FIqVgdA3t1eugvht/8bh2pSn0PoF18ghbJCBlaXJmQPowOyMV3KYu3x44Sr1jtln+Miwt9CX1RqF21VQVNjBq+iA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; dkim=pass (1024-bit key; unprotected) header.d=huawei.com header.i=@huawei.com header.a=rsa-sha256 header.s=dkim header.b=PCikQ7pI; dkim-atps=neutral; spf=pass (client-ip=113.46.200.222; helo=canpmsgout07.his.huawei.com; envelope-from=ruanjinjie@huawei.com; receiver=lists.ozlabs.org) smtp.mailfrom=huawei.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=huawei.com header.i=@huawei.com header.a=rsa-sha256 header.s=dkim header.b=PCikQ7pI; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=113.46.200.222; helo=canpmsgout07.his.huawei.com; envelope-from=ruanjinjie@huawei.com; receiver=lists.ozlabs.org) Received: from canpmsgout07.his.huawei.com (canpmsgout07.his.huawei.com [113.46.200.222]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4fjTwS50b1z2ypm for ; Sat, 28 Mar 2026 18:41:28 +1100 (AEDT) dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=7Ej/nGP6D4OZlN2NP0wOiKbhFa+CLfU7f01IuTLoNYc=; b=PCikQ7pIzeaKrzAs1XH/O8ZmZYPB9pV0fBIUYs2VLOstWE8QiBMRuVM3CIvEXipATIGW3TQ8X gcrx6UYl2RFLLYRjDgwBg3lAQFmP1VJZr1v/vi26ia8fHvOPtkTiccABS/ORh8k+igGZUfzsNYX 1sRHQpEli+zR1tX+CITCvDo= Received: from mail.maildlp.com (unknown [172.19.163.214]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4fjTnL4BJGzLlsZ; Sat, 28 Mar 2026 15:35:18 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 1B7C44056C; Sat, 28 Mar 2026 15:41:25 +0800 (CST) Received: from huawei.com (10.90.53.73) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 28 Mar 2026 15:41:22 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v11 03/11] x86/kexec: Fix potential buffer overflow in prepare_elf_headers() Date: Sat, 28 Mar 2026 15:40:05 +0800 Message-ID: <20260328074013.3589544-4-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260328074013.3589544-1-ruanjinjie@huawei.com> References: <20260328074013.3589544-1-ruanjinjie@huawei.com> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To dggpemf500011.china.huawei.com (7.185.36.131) There is a race condition between the kexec_load() system call (crash kernel loading path) and memory hotplug operations that can lead to buffer overflow and potential kernel crash. During prepare_elf_headers(), the following steps occur: 1. get_nr_ram_ranges_callback() queries current System RAM memory ranges 2. Allocates buffer based on queried count 3. prepare_elf64_ram_headers_callback() populates ranges from memblock If memory hotplug occurs between step 1 and step 3, the number of ranges can increase, causing out-of-bounds write when populating cmem->ranges[]. This happens because kexec_load() uses kexec_trylock (atomic_t) while memory hotplug uses device_hotplug_lock (mutex), so they don't serialize with each other. Just add bounds checking in prepare_elf64_ram_headers_callback() to prevent out-of-bounds (OOB) access, Fixes: 8d5f894a3108 ("x86: kexec_file: lift CRASH_MAX_RANGES limit on crash_mem buffer") Signed-off-by: Jinjie Ruan --- arch/x86/kernel/crash.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index 335fd2ee9766..7fa6d45ebe3f 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -225,6 +225,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg) { struct crash_mem *cmem = arg; + if (cmem->nr_ranges >= cmem->max_nr_ranges) + return -ENOMEM; + cmem->ranges[cmem->nr_ranges].start = res->start; cmem->ranges[cmem->nr_ranges].end = res->end; cmem->nr_ranges++; -- 2.34.1