From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 464C926ACD for ; Fri, 10 Jan 2025 03:23:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736479421; cv=none; b=lKf/3IGhWIss7XPKiX+vAyWmESpKeJPscjpsBIJqFjBzcUpTALxy7bShcV5FK8mc3JNXCp47S1zeUx3imFW+nOrpAJV4U6RQ+0zo0vm+JHJjmr3/mUIwb9ZrLeQ+09eAJQRxYStztIdp2Deve1Pnjahus0GKIMkWMukC1CwEQUc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736479421; c=relaxed/simple; bh=ty1fi+5GmvFKL6KsW7SplfmhFDDAXyU/AsI6NOgaN/4=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=mp6a0/Z/l2A3QmfSHLkSuAq0ZHSgE3uKe/yl2rTsN7uWfB9aqNCFL/YhV8F9wAuQaUTX8519OcMmNr2jTMz6+zmoP9RC7kj7m0afldQyDbko3zbns0hrLDcNdw4ZZutk1lG8oxROIaLG7ghGd5/Gsf+LHogWx1b6MNiRC5Zp5L4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I2VAUFTD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I2VAUFTD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1E3BC4CED6; Fri, 10 Jan 2025 03:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736479420; bh=ty1fi+5GmvFKL6KsW7SplfmhFDDAXyU/AsI6NOgaN/4=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=I2VAUFTDMReq3rxcdY7f3Te5QlxRL6j4CqHPjdMMVMX5elpkZz6kKF9Oiyv5UMUYW uJx9eKLbFQoYyU/0sh/XPQZ+pfb/2p1m2E2Y3Mxtp6YwL+AtDs9X9IIIqESNnMaRwF zVRhijda4+Yl1jXD2cLK9XdY8uSgERN1FBMk4USO+mj7vHOsMq2Ghq4uHogtiR7we1 AJhYF2wKs3dx2Zb9ZsL8uWn97ZYIcqYbNhCShmXWvD5bZ39zU4Cx28gqGrZV0wD9AC T56JQCJHYsvknwPtBN5YnUNeXfdvEPH45jedrEhlYl7Bj41Sri7wlxPztwGjIE9eSn 2uvACx4kpR/Yg== Message-ID: Date: Fri, 10 Jan 2025 11:23:37 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, syzbot+69f5379a1717a0b982a1@syzkaller.appspotmail.com Subject: Re: [PATCH] f2fs: fix to do sanity check correctly on i_inline_xattr_size To: Jaegeuk Kim References: <20241216134600.8308-1-chao@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 1/8/25 03:28, Jaegeuk Kim wrote: > On 12/16, Chao Yu wrote: >> syzbot reported an out-of-range access issue as below: >> >> UBSAN: array-index-out-of-bounds in fs/f2fs/f2fs.h:3292:19 >> index 18446744073709550491 is out of range for type '__le32[923]' (aka 'unsigned int[923]') >> CPU: 0 UID: 0 PID: 5338 Comm: syz.0.0 Not tainted 6.12.0-syzkaller-10689-g7af08b57bcb9 #0 >> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 >> Call Trace: >> >> __dump_stack lib/dump_stack.c:94 [inline] >> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 >> ubsan_epilogue lib/ubsan.c:231 [inline] >> __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429 >> read_inline_xattr+0x273/0x280 >> lookup_all_xattrs fs/f2fs/xattr.c:341 [inline] >> f2fs_getxattr+0x57b/0x13b0 fs/f2fs/xattr.c:533 >> vfs_getxattr_alloc+0x472/0x5c0 fs/xattr.c:393 >> ima_read_xattr+0x38/0x60 security/integrity/ima/ima_appraise.c:229 >> process_measurement+0x117a/0x1fb0 security/integrity/ima/ima_main.c:353 >> ima_file_check+0xd9/0x120 security/integrity/ima/ima_main.c:572 >> security_file_post_open+0xb9/0x280 security/security.c:3121 >> do_open fs/namei.c:3830 [inline] >> path_openat+0x2ccd/0x3590 fs/namei.c:3987 >> do_file_open_root+0x3a7/0x720 fs/namei.c:4039 >> file_open_root+0x247/0x2a0 fs/open.c:1382 >> do_handle_open+0x85b/0x9d0 fs/fhandle.c:414 >> do_syscall_x64 arch/x86/entry/common.c:52 [inline] >> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 >> entry_SYSCALL_64_after_hwframe+0x77/0x7f >> >> index: 18446744073709550491 (decimal, unsigned long long) >> = 0xfffffffffffffb9b (hexadecimal) = -1125 (decimal, long long) >> UBSAN detects that inline_xattr_addr() tries to access .i_addr[-1125]. >> >> w/ below testcase, it can reproduce this bug easily: >> - mkfs.f2fs -f -O extra_attr,flexible_inline_xattr /dev/sdb >> - mount -o inline_xattr_size=512 /dev/sdb /mnt/f2fs >> - touch /mnt/f2fs/file >> - umount /mnt/f2fs >> - inject.f2fs --node --mb i_inline --nid 4 --val 0x1 /dev/sdb >> - inject.f2fs --node --mb i_inline_xattr_size --nid 4 --val 2048 /dev/sdb >> - mount /dev/sdb /mnt/f2fs >> - getfattr /mnt/f2fs/file >> >> The root cause is if metadata of filesystem and inode were fuzzed as below: >> - extra_attr feature is enabled >> - flexible_inline_xattr feature is enabled >> - ri.i_inline_xattr_size = 2048 >> - F2FS_EXTRA_ATTR bit in ri.i_inline was not set >> >> sanity_check_inode() will skip doing sanity check on fi->i_inline_xattr_size, >> result in using invalid inline_xattr_size later incorrectly, fix it. >> >> Meanwhile, let's fix to check lower boundary for .i_inline_xattr_size w/ >> MIN_INLINE_XATTR_SIZE like we did in parse_options(). >> >> Fixes: 6afc662e68b5 ("f2fs: support flexible inline xattr size") >> Reported-by: syzbot+69f5379a1717a0b982a1@syzkaller.appspotmail.com >> Closes: https://lore.kernel.org/linux-f2fs-devel/674f4e7d.050a0220.17bd51.004f.GAE@google.com >> Signed-off-by: Chao Yu >> --- >> fs/f2fs/inode.c | 19 ++++++++++--------- >> 1 file changed, 10 insertions(+), 9 deletions(-) >> >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >> index 282fd320bdb3..29ccc64faae9 100644 >> --- a/fs/f2fs/inode.c >> +++ b/fs/f2fs/inode.c >> @@ -302,15 +302,6 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) >> F2FS_TOTAL_EXTRA_ATTR_SIZE); >> return false; >> } >> - if (f2fs_sb_has_flexible_inline_xattr(sbi) && >> - f2fs_has_inline_xattr(inode) && >> - (!fi->i_inline_xattr_size || >> - fi->i_inline_xattr_size > MAX_INLINE_XATTR_SIZE)) { >> - f2fs_warn(sbi, "%s: inode (ino=%lx) has corrupted i_inline_xattr_size: %d, max: %lu", >> - __func__, inode->i_ino, fi->i_inline_xattr_size, >> - MAX_INLINE_XATTR_SIZE); >> - return false; >> - } >> if (f2fs_sb_has_compression(sbi) && >> fi->i_flags & F2FS_COMPR_FL && >> F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, >> @@ -320,6 +311,16 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) >> } >> } >> >> + if (f2fs_sb_has_flexible_inline_xattr(sbi) && >> + f2fs_has_inline_xattr(inode) && >> + (fi->i_inline_xattr_size < MIN_INLINE_XATTR_SIZE || >> + fi->i_inline_xattr_size > MAX_INLINE_XATTR_SIZE)) { >> + f2fs_warn(sbi, "%s: inode (ino=%lx) has corrupted i_inline_xattr_size: %d, min: %u, max: %lu", > --> %lu? Thanks for fixing. I'd like to fix this in v2, meanwhile including more information from Qasdev's patch. Thanks, >> + __func__, inode->i_ino, fi->i_inline_xattr_size, >> + MIN_INLINE_XATTR_SIZE, MAX_INLINE_XATTR_SIZE); >> + return false; >> + } >> + >> if (!f2fs_sb_has_extra_attr(sbi)) { >> if (f2fs_sb_has_project_quota(sbi)) { >> f2fs_warn(sbi, "%s: corrupted inode ino=%lx, wrong feature flag: %u, run fsck to fix.", >> -- >> 2.40.1