From nobody Thu Apr 2 06:32:01 2026 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 AA054371D0A; Sat, 28 Mar 2026 07:41:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774683705; cv=none; b=ERcpvWMdnabWl+154ZwtrsOXfVYbpIsfvKyTHlh19Fh7Mh3nEUl/gVtrVkLf1+VrKV8jKCGzsVKn/s7PfbXL9Mb03mO4Ah3Mr5a7KK8XvgQYjR/I2NON6H/c0EDFROSXH5v8czLEmAQKOpp0bdzl/Hw0zfK6b/RiltzSMXrW/Hs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774683705; c=relaxed/simple; bh=r/BjhLTx/vpPxHHL8yO+ZbDBXi9Jqt2RgKcZoXT6P1s=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Kp5YhHeavH1DGtoCZDYM9I4A1AxE7lzO9vGhtnsXRzW3zjDBN3v/zq3OIQZ2WQb82KI40jCNGX/EL4xRFOpuW22f2v5I+wyoDVCqW+Akw9a2mOGeAgLi2I2PIvi32eAyckTpc6jsOkMU0i9X35niFZolR51AQluf70NxjIYBH2w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=rPlh5l6P; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=rPlh5l6P; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="rPlh5l6P"; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="rPlh5l6P" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=7Kwc6kWIjE6MMFJP+OfVcLTnCUv+ekJ3y6ZVFx802F8=; b=rPlh5l6P/r0lCaYwhte4yShjLrdwYBNU0lmIIgw5zLcvDsIThOK9DhT/uaKtGrhCHIM2m/T2E E/c7DL3vdFGbipfioCcdgsazyLS5iJjEmcOCqlzDVeWHjNYlk59gPZS+xwcmZ6tAuW17/cQDjHA 1aexox4eHyMo0rEmFdCoOYA= Received: from canpmsgout08.his.huawei.com (unknown [172.19.92.156]) by szxga01-in.huawei.com (SkyGuard) with ESMTPS id 4fjTwW11bcz1BFSs; Sat, 28 Mar 2026 15:41:31 +0800 (CST) dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=7Kwc6kWIjE6MMFJP+OfVcLTnCUv+ekJ3y6ZVFx802F8=; b=rPlh5l6P/r0lCaYwhte4yShjLrdwYBNU0lmIIgw5zLcvDsIThOK9DhT/uaKtGrhCHIM2m/T2E E/c7DL3vdFGbipfioCcdgsazyLS5iJjEmcOCqlzDVeWHjNYlk59gPZS+xwcmZ6tAuW17/cQDjHA 1aexox4eHyMo0rEmFdCoOYA= Received: from mail.maildlp.com (unknown [172.19.163.214]) by canpmsgout08.his.huawei.com (SkyGuard) with ESMTPS id 4fjTnS5Lt2zmV79; Sat, 28 Mar 2026 15:35:24 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 850984056C; Sat, 28 Mar 2026 15:41:33 +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 15:41:30 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v11 06/11] LoongArch: kexec: Fix potential buffer overflow in prepare_elf_headers() Date: Sat, 28 Mar 2026 15:40:08 +0800 Message-ID: <20260328074013.3589544-7-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> 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: kwepems100001.china.huawei.com (7.221.188.238) To dggpemf500011.china.huawei.com (7.185.36.131) Content-Type: text/plain; charset="utf-8" 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. The first for_each_mem_range() queries current System RAM memory ranges 2. Allocates buffer based on queried count 3. The 2st for_each_mem_range() 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 to prevent out-of-bounds access. Fixes: 1bcca8620a91 ("LoongArch: Add crash dump support for kexec_file") Signed-off-by: Jinjie Ruan --- arch/loongarch/kernel/machine_kexec_file.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/ke= rnel/machine_kexec_file.c index 5584b798ba46..167392c1da33 100644 --- a/arch/loongarch/kernel/machine_kexec_file.c +++ b/arch/loongarch/kernel/machine_kexec_file.c @@ -75,6 +75,11 @@ static int prepare_elf_headers(void **addr, unsigned lon= g *sz) cmem->max_nr_ranges =3D nr_ranges; cmem->nr_ranges =3D 0; for_each_mem_range(i, &start, &end) { + if (cmem->nr_ranges >=3D cmem->max_nr_ranges) { + ret =3D -ENOMEM; + goto out; + } + cmem->ranges[cmem->nr_ranges].start =3D start; cmem->ranges[cmem->nr_ranges].end =3D end - 1; cmem->nr_ranges++; --=20 2.34.1