From patchwork Tue Jul 18 13:10:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baokun Li X-Patchwork-Id: 1809248 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=2404:9400:2221:ea00::3; helo=gandalf.ozlabs.org; envelope-from=srs0=cyfb=de=vger.kernel.org=linux-ext4-owner@ozlabs.org; receiver=) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4R4ztC59Djz20Cs for ; Tue, 18 Jul 2023 23:13:55 +1000 (AEST) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4R4ztC4xv6z4wZw for ; Tue, 18 Jul 2023 23:13:55 +1000 (AEST) Received: by gandalf.ozlabs.org (Postfix) id 4R4ztC4vLsz4wxy; Tue, 18 Jul 2023 23:13:55 +1000 (AEST) Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: gandalf.ozlabs.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: gandalf.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=ozlabs.org) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4R4ztC4pcTz4wZw for ; Tue, 18 Jul 2023 23:13:55 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232644AbjGRNNz (ORCPT ); Tue, 18 Jul 2023 09:13:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231759AbjGRNNq (ORCPT ); Tue, 18 Jul 2023 09:13:46 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33073D1; Tue, 18 Jul 2023 06:13:44 -0700 (PDT) Received: from dggpeml500021.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4R4zrL6dbnzVjcX; Tue, 18 Jul 2023 21:12:18 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Tue, 18 Jul 2023 21:13:40 +0800 From: Baokun Li To: CC: , , , , , , , , , Subject: [PATCH 2/4] ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow Date: Tue, 18 Jul 2023 21:10:50 +0800 Message-ID: <20230718131052.283350-3-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230718131052.283350-1-libaokun1@huawei.com> References: <20230718131052.283350-1-libaokun1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500021.china.huawei.com (7.185.36.21) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org When we calculate the end position of ext4_free_extent, this position may be exactly where ext4_lblk_t (i.e. uint) overflows. For example, if ac_g_ex.fe_logical is 4294965248 and ac_orig_goal_len is 2048, then the computed end is 0x100000000, which is 0. If ac->ac_o_ex.fe_logical is not the first case of adjusting the best extent, that is, new_bex_end > 0, the following BUG_ON will be triggered: ========================================================= kernel BUG at fs/ext4/mballoc.c:5116! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 673 Comm: xfs_io Tainted: G E 6.5.0-rc1+ #279 RIP: 0010:ext4_mb_new_inode_pa+0xc5/0x430 Call Trace: ext4_mb_use_best_found+0x203/0x2f0 ext4_mb_try_best_found+0x163/0x240 ext4_mb_regular_allocator+0x158/0x1550 ext4_mb_new_blocks+0x86a/0xe10 ext4_ext_map_blocks+0xb0c/0x13a0 ext4_map_blocks+0x2cd/0x8f0 ext4_iomap_begin+0x27b/0x400 iomap_iter+0x222/0x3d0 __iomap_dio_rw+0x243/0xcb0 iomap_dio_rw+0x16/0x80 ========================================================= A simple reproducer demonstrating the problem: mkfs.ext4 -F /dev/sda -b 4096 100M mount /dev/sda /tmp/test fallocate -l1M /tmp/test/tmp fallocate -l10M /tmp/test/file fallocate -i -o 1M -l16777203M /tmp/test/file fsstress -d /tmp/test -l 0 -n 100000 -p 8 & sleep 10 && killall -9 fsstress rm -f /tmp/test/tmp xfs_io -c "open -ad /tmp/test/file" -c "pwrite -S 0xff 0 8192" We declare new_bex_start and new_bex_end as correct types and use fex_end() to avoid the problems caused by the ext4_lblk_t overflow above. Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()") Signed-off-by: Baokun Li --- fs/ext4/mballoc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index eb7f5d35ef96..2090e5e7ba58 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -5076,8 +5076,8 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) pa = ac->ac_pa; if (ac->ac_b_ex.fe_len < ac->ac_orig_goal_len) { - int new_bex_start; - int new_bex_end; + ext4_lblk_t new_bex_start; + loff_t new_bex_end; /* we can't allocate as much as normalizer wants. * so, found space must get proper lstart @@ -5096,8 +5096,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) * still cover original start * 3. Else, keep the best ex at start of original request. */ - new_bex_end = ac->ac_g_ex.fe_logical + - EXT4_C2B(sbi, ac->ac_orig_goal_len); + new_bex_end = fex_end(sbi, &ac->ac_g_ex, &ac->ac_orig_goal_len); new_bex_start = new_bex_end - EXT4_C2B(sbi, ac->ac_b_ex.fe_len); if (ac->ac_o_ex.fe_logical >= new_bex_start) goto adjust_bex; @@ -5117,8 +5116,8 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); - BUG_ON(new_bex_end > (ac->ac_g_ex.fe_logical + - EXT4_C2B(sbi, ac->ac_orig_goal_len))); + BUG_ON(new_bex_end > + fex_end(sbi, &ac->ac_g_ex, &ac->ac_orig_goal_len)); } pa->pa_lstart = ac->ac_b_ex.fe_logical;