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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80E4FC433E0 for ; Fri, 12 Mar 2021 15:47:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F83364FDD for ; Fri, 12 Mar 2021 15:47:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232590AbhCLPqm (ORCPT ); Fri, 12 Mar 2021 10:46:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231928AbhCLPql (ORCPT ); Fri, 12 Mar 2021 10:46:41 -0500 Received: from laurent.telenet-ops.be (laurent.telenet-ops.be [IPv6:2a02:1800:110:4::f00:19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7628C061574 for ; Fri, 12 Mar 2021 07:46:40 -0800 (PST) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed20:f9e2:c536:b8cc:fbbc]) by laurent.telenet-ops.be with bizsmtp id fTmc2400D1ACAb301Tmcmh; Fri, 12 Mar 2021 16:46:38 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1lKjzn-0079iK-SM; Fri, 12 Mar 2021 16:46:35 +0100 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1lKjzn-00ErPJ-8j; Fri, 12 Mar 2021 16:46:35 +0100 From: Geert Uytterhoeven To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Atish Patra Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] RISC-V: Fix out-of-bounds accesses in init_resources() Date: Fri, 12 Mar 2021 16:46:34 +0100 Message-Id: <20210312154634.3541844-1-geert@linux-m68k.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org init_resources() allocates an array of resources, based on the current total number of memory regions and reserved memory regions. However, allocating this array using memblock_alloc() might increase the number of reserved memory regions. If that happens, populating the array later based on the new number of regions will cause out-of-bounds writes beyond the end of the allocated array. Fix this by allocating one more entry, which may or may not be used. Fixes: 797f0375dd2ef5cd ("RISC-V: Do not allocate memblock while iterating reserved memblocks") Signed-off-by: Geert Uytterhoeven --- Tested on vexriscv, which works now using L1_CACHE_SHIFT = 6, too. This issue may show up during early boot as: Unable to handle kernel paging request at virtual address c8000008 Oops [#1] CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0-orangecrab-00023-g7c4fc8e3e982-dirty #137 epc: c04d6660 ra : c04d6560 sp : c05ddf70 gp : c0678bc0 tp : c05e5b40 t0 : c8000000 t1 : 00030000 t2 : ffffffff s0 : c05ddfc0 s1 : c8000000 a0 : 00000000 a1 : c7ffffe0 a2 : 00000005 a3 : 00000001 a4 : 0000000c a5 : 00000000 a6 : c04fe000 a7 : 0000000c s2 : c04fe098 s3 : 000000a0 s4 : c7ffff60 s5 : c04fe0dc s6 : 80000200 s7 : c059f1d4 s8 : 81000200 s9 : c059f1f0 s10: 80000200 s11: c059f1d4 t3 : 405dbb60 t4 : c05e6f08 t5 : 81000200 t6 : 40501000 status: 00000100 badaddr: c8000008 cause: 0000000f random: get_random_bytes called from print_oops_end_marker+0x38/0x7c with crng_init=0 ---[ end trace 0000000000000000 ]--- or much later as: Unable to handle kernel paging request at virtual address 69726573 --- arch/riscv/kernel/setup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index e85bacff1b5075ee..f8f15332caa20263 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -147,7 +147,8 @@ static void __init init_resources(void) bss_res.end = __pa_symbol(__bss_stop) - 1; bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; - mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res); + /* + 1 as memblock_alloc() might increase memblock.reserved.cnt */ + mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt + 1) * sizeof(*mem_res); mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES); if (!mem_res) panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz); -- 2.25.1