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 5C9E51D63EB for ; Tue, 7 Jan 2025 19:28:09 +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=1736278089; cv=none; b=oEvmc8VjA6wl7dgYgRn7T8JzZoZRltJ9khDexlC6YMMHs1E32Kxp9MLYWozOZC8zR95clMD7iUCN8eyvB/+oCC2Oinha235H5WNcTBEVsUmTSset8/+Jms/pnDe4Pab+ESCSsP5jzakJgZjIXB+Vv1y8GbVnraiND+ewIIGo19I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736278089; c=relaxed/simple; bh=y6c62K5alUDjVorsTzUUY3jL0tfe4CLJ0uI+5Vv+iQc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=J+ZWnRv0vopwER0oeLO+dWq1fXv6Q5zA8yPpew+kV5A8+45O1IduqSZHUvT+fCeHPiVOx/mBCDVrZKAGTMXSbzGDrZYENlPmYPruEwGeHUkF6BoV9LyMnYi337sOX+2SB+dxsJK6o3d4MqTyqxFxf5d13jQpJcWDey93U7LvjxA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N03V7pZS; 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="N03V7pZS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A970FC4CED6; Tue, 7 Jan 2025 19:28:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736278088; bh=y6c62K5alUDjVorsTzUUY3jL0tfe4CLJ0uI+5Vv+iQc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=N03V7pZSBgs00q/ze0RM8UdByBlb/AuIXH8/tv8PmQlTyCJfJ71mhkX6d3FH9xGTp fIihIxb68FjVGw9GvypFbmcfoXvRgY2RLUtu4IHo2ii8Y7oOw6W5S/LDwu2cvaMtF1 JLPCjpOe3x/XQyW5wL7RtShe1q1/wXYLV+Gpl2v8q8F53xUTxZoujqPzkVxJRxsYXC 1BmONgLqTqIOAcNRdT1d07cv9H3t7a0XwGvjTNpKcZcp7FmNoljGIVIEyz2heVCzXC GEjdvdQ4T1udLXfE3nKYMq9cD9dXEh04gby5sgh8m1hTpm0/EMKm1u4OxThc19uzxA ub6Ef5tjVNieQ== Date: Tue, 7 Jan 2025 19:28:06 +0000 From: Jaegeuk Kim To: Chao Yu Cc: 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 Message-ID: References: <20241216134600.8308-1-chao@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241216134600.8308-1-chao@kernel.org> 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? > + __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