From patchwork Tue Mar 29 03:29:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Xuenan X-Patchwork-Id: 12794414 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1572C433EF for ; Tue, 29 Mar 2022 03:11:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231483AbiC2DNM (ORCPT ); Mon, 28 Mar 2022 23:13:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231478AbiC2DNK (ORCPT ); Mon, 28 Mar 2022 23:13:10 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C8E523DEB1; Mon, 28 Mar 2022 20:11:25 -0700 (PDT) Received: from kwepemi500016.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KSDy14LShz9snJ; Tue, 29 Mar 2022 11:07:21 +0800 (CST) Received: from kwepemm600004.china.huawei.com (7.193.23.242) by kwepemi500016.china.huawei.com (7.221.188.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 29 Mar 2022 11:11:23 +0800 Received: from huawei.com (10.175.124.27) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 29 Mar 2022 11:11:22 +0800 From: Guo Xuenan To: CC: , , , , , , , Subject: [PATCH v2] fs: fix an infinite loop in iomap_fiemap Date: Tue, 29 Mar 2022 11:29:57 +0800 Message-ID: <20220329032957.2694944-1-guoxuenan@huawei.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20220320162641.GB8182@magnolia> References: <20220320162641.GB8182@magnolia> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600004.china.huawei.com (7.193.23.242) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org when get fiemap starting from MAX_LFS_FILESIZE, (maxbytes - *len) < start will always true , then *len set zero. because of start offset is byhond file size, for erofs filesystem it will always return iomap.length with zero,iomap iterate will enter infinite loop. it is necessary cover this corner case to avoid this situation. ------------[ cut here ]------------ WARNING: CPU: 7 PID: 905 at fs/iomap/iter.c:35 iomap_iter+0x97f/0xc70 Modules linked in: xfs erofs CPU: 7 PID: 905 Comm: iomap Tainted: G W 5.17.0-rc8 #27 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:iomap_iter+0x97f/0xc70 Code: 85 a1 fc ff ff e8 71 be 9c ff 0f 1f 44 00 00 e9 92 fc ff ff e8 62 be 9c ff 0f 0b b8 fb ff ff ff e9 fc f8 ff ff e8 51 be 9c ff <0f> 0b e9 2b fc ff ff e8 45 be 9c ff 0f 0b e9 e1 fb ff ff e8 39 be RSP: 0018:ffff888060a37ab0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff888060a37bb0 RCX: 0000000000000000 RDX: ffff88807e19a900 RSI: ffffffff81a7da7f RDI: ffff888060a37be0 RBP: 7fffffffffffffff R08: 0000000000000000 R09: ffff888060a37c20 R10: ffff888060a37c67 R11: ffffed100c146f8c R12: 7fffffffffffffff R13: 0000000000000000 R14: ffff888060a37bd8 R15: ffff888060a37c20 FS: 00007fd3cca01540(0000) GS:ffff888108780000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020010820 CR3: 0000000054b92000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: iomap_fiemap+0x1c9/0x2f0 erofs_fiemap+0x64/0x90 [erofs] do_vfs_ioctl+0x40d/0x12e0 __x64_sys_ioctl+0xaa/0x1c0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae ---[ end trace 0000000000000000 ]--- watchdog: BUG: soft lockup - CPU#7 stuck for 26s! [iomap:905] Reported-by: Hulk Robot Signed-off-by: Guo Xuenan Reviewed-by: Christoph Hellwig --- fs/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ioctl.c b/fs/ioctl.c index 090bf47606ab..80ac36aea913 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -173,7 +173,7 @@ int fiemap_prep(struct inode *inode, struct fiemap_extent_info *fieinfo, if (*len == 0) return -EINVAL; - if (start > maxbytes) + if (start >= maxbytes) return -EFBIG; /*