From nobody Thu Apr 2 15:37:45 2026 Received: from canpmsgout07.his.huawei.com (canpmsgout07.his.huawei.com [113.46.200.222]) (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 AB6AF389102; Thu, 2 Apr 2026 07:26:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.222 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775114763; cv=none; b=etZnoa4SzSpmp7b/HAyM2YwAP+jVaeoaz4dHefszqC8WYKV3UJj3rbblVmD3IdBVnmJ5GjplpuLuUBLSKCwuS2fQX0iIgTPF3oiwRI6of3dPqCRBFTYBqIzgRaGZz7S6z3950ws1DHHvOLjLfO9Rf6puEV6BJPgPj9E6Usx0nIA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775114763; c=relaxed/simple; bh=ABVFtDNau3Hz2tXwMuxZCb1FWI/K8Uq9NTwQLWJhFl4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=AwdelEIYup2lDH+MhUSOmyxNYM6/2aye4wzWQ7teCPJ/JRbQ/lCuOgtzr0F/nsqTaMhq+SXAJWZkmtYTCoJ+XMKAQVxf70P/dyt4t9nRSuVdsicvjxvSQQzbmxOe7yT8ydS1lG1wHJeQsrkNqOB4lQjNInvDIxQ7OuVYA9D/GiQ= 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=Hh6dkgZQ; arc=none smtp.client-ip=113.46.200.222 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="Hh6dkgZQ" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=2CVL6M7h4vY4kI4KzhS6vFtDcU8tP4DeufZv1p45yx8=; b=Hh6dkgZQcTT1fQKxm1gP5TRn0Ugnr1hO9wW6ndbdksU/Dokcvl9DqG9mj5IhUFYQyRr6MBv6I quSBZOA4Eb8bx6CLRE0Gc/xp9qPblaGRburMfLWy5Dff6nsQC2yFAn386Ocl3CwKCnHWmkBVHAs ZqkM3+yoksIFhlU8Cv8y86k= Received: from mail.maildlp.com (unknown [172.19.163.15]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4fmYC93KVjzLlTb; Thu, 2 Apr 2026 15:19:49 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 10FCD40571; Thu, 2 Apr 2026 15:25:59 +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; Thu, 2 Apr 2026 15:25:55 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v12 05/15] riscv: kexec_file: Fix potential buffer overflow in prepare_elf_headers() Date: Thu, 2 Apr 2026 15:26:51 +0800 Message-ID: <20260402072701.628293-6-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260402072701.628293-1-ruanjinjie@huawei.com> References: <20260402072701.628293-1-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: kwepems100002.china.huawei.com (7.221.188.206) 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. 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: 8acea455fafa ("RISC-V: Support for kexec_file on panic") Reviewed-by: Guo Ren Signed-off-by: Jinjie Ruan --- arch/riscv/kernel/machine_kexec_file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/mac= hine_kexec_file.c index 3f7766057cac..773a1cba8ba0 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -48,6 +48,9 @@ static int prepare_elf64_ram_headers_callback(struct reso= urce *res, void *arg) { struct crash_mem *cmem =3D arg; =20 + if (cmem->nr_ranges >=3D cmem->max_nr_ranges) + return -ENOMEM; + cmem->ranges[cmem->nr_ranges].start =3D res->start; cmem->ranges[cmem->nr_ranges].end =3D res->end; cmem->nr_ranges++; --=20 2.34.1