From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-112.freemail.mail.aliyun.com (out30-112.freemail.mail.aliyun.com [115.124.30.112]) (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 97E2C63D for ; Mon, 27 May 2024 02:33:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.112 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716777195; cv=none; b=XuH+rxFhL54FSExhtX3Tl04JuYM9/LubE2RYVvcCVKiWeppG5dSZsMJGgOydz+qnQkM+qL6NiP0F42IJta1GDCz+OLrmZln0lf44ZEb3FQN6toCFxlvAvQkoT9Y598qOZW9KMkWxYGJ6+ZWxTRpLsE+7zd8JWSGNfmwQZUqkBVg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716777195; c=relaxed/simple; bh=wZH1DvPetZYfXxeV5CD1cBhK0z4ymdmb9HxMSr8feM0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OiZaxTQZSu5qHYCg6E0zm7t6OIcjwZWySxkAMbNDJfkd7XqxB7as/wxU7QZSGK2uSG67noWKNaa8MAJ4+AgmlnLAEJL1Bsvd+VqgVYEdbfpiM3vVw52IEB4Gr2mrvPefZ9YP0oNSjbsWlGQZ67rDItsuaBCoJB5+/7SqhADUoa0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=xlmUq9nL; arc=none smtp.client-ip=115.124.30.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="xlmUq9nL" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1716777184; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=+XXzhyIEHU938zz/Rj1obzB9ZpTYUZUMj9NcuIVQ83k=; b=xlmUq9nLVQqiQed9qK+K9FImFeRazBn5TX03KtsYHGiD5iWvlarnPzO0MxmWelPXaBufb9dlYrv1oTrDCQkQgAn2vub2YHAT2jgtaL9fR+JuY/inqrt4Av25abZpdfe6KN/XFCEbL4JteRifYV9BolhK+j0y4lYdOrtXuJBFUqM= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R241e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037067111;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0W7Ctmc1_1716777182; Received: from 30.221.129.180(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0W7Ctmc1_1716777182) by smtp.aliyun-inc.com; Mon, 27 May 2024 10:33:03 +0800 Message-ID: <059f5953-4f6d-4580-9bc5-685a03364987@linux.alibaba.com> Date: Mon, 27 May 2024 10:33:02 +0800 Precedence: bulk X-Mailing-List: ocfs2-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] ocfs2: add bounds checking to ocfs2_search_dirblock() To: lei lu Cc: mark@fasheh.com, jlbec@evilplan.org, ocfs2-devel@lists.linux.dev, Greg Kroah-Hartman References: <20240526110631.10618-1-llfamsec@gmail.com> Content-Language: en-US From: Joseph Qi In-Reply-To: <20240526110631.10618-1-llfamsec@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/26/24 7:06 PM, lei lu wrote: > Add a check to make sure all members of the ocfs2_dir_entry > don't stray beyond valid memory region. > > Signed-off-by: lei lu > --- > fs/ocfs2/dir.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c > index d620d4c53c6f..385576d86983 100644 > --- a/fs/ocfs2/dir.c > +++ b/fs/ocfs2/dir.c > @@ -358,6 +358,17 @@ static inline int ocfs2_search_dirblock(struct buffer_head *bh, > > de = (struct ocfs2_dir_entry *) de_buf; > > + if (unlikely(de_buf + OCFS2_DIR_MEMBER_LEN > dlimit)) { > + ret = -1; > + goto bail; > + } It seems that this check can be moved to: while (de_buf < dlimit - OCFS2_DIR_MEMBER_LEN) { ... } > + de_len = le16_to_cpu(de->rec_len); > + if (unlikely(de_buf + de_len > dlimit) || dlimit = de_buf + bytes; So here you mean check de_len < bytes? Or should we check more precisely, like in ocfs2_check_dir_entry(): (de - bh->b_data) + de_len > bytes - OCFS2_DIR_REC_LEN(de->name_len) > + unlikely(de_len < OCFS2_DIR_REC_LEN(de->name_len))) { This is already done in ocfs2_check_dir_entry(). > + ret = -1; > + goto bail; > + } > + > if (de_buf + namelen <= dlimit && > ocfs2_match(namelen, name, de)) { > /* found a match - just to be sure, do a full check */ > @@ -371,7 +382,6 @@ static inline int ocfs2_search_dirblock(struct buffer_head *bh, > } > > /* prevent looping on a bad block */ > - de_len = le16_to_cpu(de->rec_len); > if (de_len <= 0) { > ret = -1; > goto bail;