From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) (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 988552D238A for ; Fri, 12 Jun 2026 01:02:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781226152; cv=none; b=uauhH3JhK+Kjb5mcJ5lw80eX911iOoQB1jk6VashUpl1K0Vs8RJiBiYLFvwlQ0igolW0fo8orAIdZioaRNvL+cPEII7bw6gqMJJUFxmgK16UdqjstOYtpk2tixHAtBHStXHlQzFamHI4q9Sexuv+t2XLfN4fkH61MqjHYWq6WKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781226152; c=relaxed/simple; bh=+Dg+/4H6lPCRTI8lbBz2r+TrZQuiFYCkgMZJzJSbiGk=; h=Message-ID:Date:MIME-Version:Subject:To:References:Cc:From: In-Reply-To:Content-Type; b=UF0O1POHNmWwBccUcQty1X+UdgRy9E3aGi5CNMgE9sA7jU1Uf4ZjWZ46PCfp9t4bDp3VOBdEWQG5XeLZfiJeSin26r3/GCqxG9g2fvPJFQUIKKYI0dPHHsbfG0/oUm9lKTjLm21DC9qws9d5TZqwI3u1ztUKsfQQAv3zZvF2wvM= 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=pq+7IaSC; arc=none smtp.client-ip=115.124.30.100 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="pq+7IaSC" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1781226141; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=O5Q7Kd11BUZ1uj3aFJyfEkkO0CyBezvD6IcqVAJU0OI=; b=pq+7IaSCBfQjKfNwZUIWH10fpGxAQuXLVIfL4GCY2d61ly4FOeKHy9sPy7DCVv3hfYGVezNkD2gMigB3itoJFVJKLFCrXQS2Z/Yw0OgrFJEzb34gZmZmFOXR5Z9kKTKvs+emvF9Ldr7JHhnV19nERlAaZhmuaqRBQw7GgXeImms= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045133197;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0X4f9joK_1781226140; Received: from 30.221.145.30(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0X4f9joK_1781226140 cluster:ay36) by smtp.aliyun-inc.com; Fri, 12 Jun 2026 09:02:20 +0800 Message-ID: Date: Fri, 12 Jun 2026 09:02:18 +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 Subject: Re: [PATCH v4] ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec To: Ian Bridges , akpm References: Cc: Mark Fasheh , Joel Becker , "ocfs2-devel@lists.linux.dev" , "linux-kernel@vger.kernel.org" From: Joseph Qi In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/11/26 8:23 AM, Ian Bridges wrote: > [BUG] > On-disk corruption setting l_next_free_rec to 0 in an inode's embedded > extent list triggers a UBSAN panic on the next write to that file. > > [CAUSE] > ocfs2_sum_rightmost_rec() computes > i = le16_to_cpu(el->l_next_free_rec) - 1 > and accesses el->l_recs[i] without validating i. When l_next_free_rec > is 0, i becomes -1; when l_next_free_rec exceeds l_count, i falls > past the end of the array. Either case violates the > __counted_by_le(l_count) annotation on l_recs[] and triggers UBSAN. > > [FIX] > Validate the inode's embedded extent list when the inode is read, in > ocfs2_validate_inode_block(): l_count must be non-zero and no larger > than the inode block can hold, and l_next_free_rec must not exceed > l_count. A corrupt list is rejected at read time, before the b-tree > code can index l_recs[] out of bounds. > > Reported-by: syzbot+be16e33db01e6644db7a@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=be16e33db01e6644db7a > Cc: stable@vger.kernel.org > Signed-off-by: Ian Bridges Looks fine. Reviewed-by: Joseph Qi > --- > Changes in 4: > - Update commit message to use "inline" instead of "embedded" Typo here? I think you mean 'embedded' instead of 'inline'. > > v3: https://lore.kernel.org/all/aibMhhAH-swS38i0@dev/ > > fs/ocfs2/inode.c | 32 ++++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c > index a510a0eb1adc..aff95efd78e7 100644 > --- a/fs/ocfs2/inode.c > +++ b/fs/ocfs2/inode.c > @@ -1559,6 +1559,38 @@ int ocfs2_validate_inode_block(struct super_block *sb, > goto bail; > } > > + if (ocfs2_dinode_has_extents(di)) { > + struct ocfs2_extent_list *el = &di->id2.i_list; > + u16 count = le16_to_cpu(el->l_count); > + u16 next_free = le16_to_cpu(el->l_next_free_rec); > + > + if (count == 0) { > + rc = ocfs2_error(sb, > + "Invalid dinode %llu: extent list l_count is zero\n", > + (unsigned long long)bh->b_blocknr); > + goto bail; > + } > + /* > + * The exact capacity depends on i_xattr_inline_size, another > + * unvalidated on-disk field. Inline xattrs only shrink the > + * list, so the no-xattr maximum is a safe upper bound that a > + * valid l_count never exceeds. > + */ > + if (count > ocfs2_extent_recs_per_inode(sb)) { > + rc = ocfs2_error(sb, > + "Invalid dinode %llu: extent list l_count %u exceeds max %u\n", > + (unsigned long long)bh->b_blocknr, count, > + ocfs2_extent_recs_per_inode(sb)); > + goto bail; > + } > + if (next_free > count) { > + rc = ocfs2_error(sb, > + "Invalid dinode %llu: extent list l_next_free_rec %u exceeds l_count %u\n", > + (unsigned long long)bh->b_blocknr, next_free, count); > + goto bail; > + } > + } > + > rc = 0; > > bail: