From patchwork Sat Dec 11 15:40:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Yu X-Patchwork-Id: 524237 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 68F22C433EF for ; Sat, 11 Dec 2021 15:41:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230224AbhLKPlM (ORCPT ); Sat, 11 Dec 2021 10:41:12 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:56498 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbhLKPlL (ORCPT ); Sat, 11 Dec 2021 10:41:11 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7330DB807E7; Sat, 11 Dec 2021 15:41:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97CE0C004DD; Sat, 11 Dec 2021 15:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639237269; bh=/yzdGEDxV8GD43o8d2iS7Fpu19V4hNZBpBWubgsd76I=; h=From:To:Cc:Subject:Date:From; b=kXDkugGdSQy97nMVvk9XMQvGnZ92/Z00n8oJAp5IrpPX9xpIp9YxlYkvoRa1CBdW0 LKeRZQbECeyUagoUAmw/QYcAjYbdyAurISTA1jzXouVvnq4tIDDjuZzmxtIDGbOBBf ZaNWx7eXtrylPUFIfsk75oAYCVt12gbxF1Tr1E29U58LIckXQYdcub8yMZma4pUny8 L6yBtR/Rkl6ZNTLyKZXQJ85WgLazhE+ZvADr2mQZcxwE3TnSLIrWEO0lGD4p1T2ZTR cWmndM8kjPBpZ9ScrbPp4mfSrrIzfVVjVEHOhh8evIPmAtg3I3jjlzL+aip64Cr9ID 9zEUW+wZvI2Tw== From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu , stable@vger.kernel.org, Wenqing Liu Subject: [PATCH] f2fs: fix to do sanity check on last xattr entry in __f2fs_setxattr() Date: Sat, 11 Dec 2021 23:40:59 +0800 Message-Id: <20211211154059.7173-1-chao@kernel.org> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org As Wenqing Liu reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215235 - Overview page fault in f2fs_setxattr() when mount and operate on corrupted image - Reproduce tested on kernel 5.16-rc3, 5.15.X under root 1. unzip tmp7.zip 2. ./single.sh f2fs 7 Sometimes need to run the script several times - Kernel dump loop0: detected capacity change from 0 to 131072 F2FS-fs (loop0): Found nat_bits in checkpoint F2FS-fs (loop0): Mounted with checkpoint version = 7548c2ee BUG: unable to handle page fault for address: ffffe47bc7123f48 RIP: 0010:kfree+0x66/0x320 Call Trace: __f2fs_setxattr+0x2aa/0xc00 [f2fs] f2fs_setxattr+0xfa/0x480 [f2fs] __f2fs_set_acl+0x19b/0x330 [f2fs] __vfs_removexattr+0x52/0x70 __vfs_removexattr_locked+0xb1/0x140 vfs_removexattr+0x56/0x100 removexattr+0x57/0x80 path_removexattr+0xa3/0xc0 __x64_sys_removexattr+0x17/0x20 do_syscall_64+0x37/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is in __f2fs_setxattr(), we missed to do sanity check on last xattr entry, result in out-of-bound memory access during updating inconsistent xattr data of target inode. After the fix, it can detect such xattr inconsistency as below: F2FS-fs (loop11): inode (7) has invalid last xattr entry, entry_size: 60676 F2FS-fs (loop11): inode (8) has corrupted xattr F2FS-fs (loop11): inode (8) has corrupted xattr F2FS-fs (loop11): inode (8) has invalid last xattr entry, entry_size: 47736 Cc: stable@vger.kernel.org Reported-by: Wenqing Liu Signed-off-by: Chao Yu --- fs/f2fs/xattr.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index e348f33bcb2b..c544100643c8 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -684,8 +684,17 @@ static int __f2fs_setxattr(struct inode *inode, int index, } last = here; - while (!IS_XATTR_LAST_ENTRY(last)) + while (!IS_XATTR_LAST_ENTRY(last)) { + if ((void *)(last) + sizeof(__u32) > last_base_addr || + (void *)XATTR_NEXT_ENTRY(last) > last_base_addr) { + f2fs_err(F2FS_I_SB(inode), "inode (%lu) has invalid last xattr entry, entry_size: %lu", + inode->i_ino, ENTRY_SIZE(last)); + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + error = -EFSCORRUPTED; + goto exit; + } last = XATTR_NEXT_ENTRY(last); + } newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);