From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 EC7D1282F1C for ; Wed, 26 Aug 2026 01:46:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787708793; cv=none; b=CzROkDph8wJT4k/5lwqrlvNWfF1w71oB+9sjjqQzFruDZAnIF052xy7x84kEOnF1OlmmSBJ3ZCJ8JMD0GC2EU9r0YHMOM4tmYqyIYRuZuVgmtQsbRpPnBf2jsLsTPvEyDiRnYnJmx1Q/+1JxgHeahqIepxoeVmMWR8VvuypFVxY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787708793; c=relaxed/simple; bh=tAHEUfXWX8PQ5gscgLDOWRfbZ/rIlsAdKEdUPvaXT7o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qKqGEzltC9CyGqbboXpfBJp8zTsjBiBptfW5UbLzR5eSqOU2mc3bAYSvjV2mZB8d1SXNRBJmjhGXYXpzNs3R8cLxpwEWkyVD0ZzMIdZCW8FX94PaKOXOm4YYgt5RJVBdXhkdgf7Cmvb05hSIT05QI3n6u1E2QoCamjXQeWjeeAM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NHBME54g; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NHBME54g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 308841F00A3D; Wed, 26 Aug 2026 01:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787708791; bh=ul8CI+Eb4z82fxh8sLeQ4YdtcJdmyaF/tioYRKM9LSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NHBME54g2kmlL8kyWCw0MRnhftJQViBB6aSkzraWTa9Y52tWuqOv1eCV5GH/q2Thm 00sylyIY9p3DX588jLqFX6VaWBG7O+RCYC8B7J08gvJgtmlI/Jf1gKISmYgY5qLgaC d9XF1Lt0oxL+7AgyvG1NQZ7NoE4kXQkNZ8MpqtqP8upNnPzbfwH2NFbukJPw/tsQv2 cM/JGjjz9oKwqTBdB50c/Y+9O+tJr7HHYSsSx/qhKdZjN63mIJK/BqL9HjTnTdS7e/ 02ftnLRMaowu48fB7lfnFAf9CGhE7ZD2E5Hx7cDc3OmM2Sb/gW+kX/gUrfugzNK1+7 4Bhe62Rqk1bZg== From: Sasha Levin To: stable@vger.kernel.org Cc: Ryusuke Konishi , syzbot+c37bed40868932d790e9@syzkaller.appspotmail.com, wuyankun , Viacheslav Dubeyko , Sasha Levin Subject: [PATCH 5.15.y 2/2] nilfs2: reject invalid block index in GC ioctl Date: Tue, 25 Aug 2026 21:46:27 -0400 Message-ID: <20260826014627.1462629-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260826014627.1462629-1-sashal@kernel.org> References: <2026082454-grope-ground-b6d7@gregkh> <20260826014627.1462629-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ryusuke Konishi [ Upstream commit a1735eae55448bc79c2da6593455791e886f6ed8 ] Syzbot reported list corruption caused by a double list_add_tail() call on bh->b_assoc_buffers within nilfs_lookup_dirty_data_buffers(). Analysis revealed that the root cause was the insertion of a page/folio with a page index of ULONG_MAX into the page cache via the GC ioctl. filemap_get_folios_tag(), called by nilfs_lookup_dirty_data_buffers(), repeatedly detects a dirty folio with a page index of ULONG_MAX due to index wrap-around, leading to duplicate processing of dirty buffers. As a preparatory step, the GC ioctl loads the page/folio of the block to be moved during GC and inserts it into the page cache based on information in the nilfs_vdesc structure passed as an argument. Normally, this does not cause issues because the user-space GC library configures the nilfs_vdesc structure properly. However, since there is no range check on the parameters determining the page index, a request with artificially crafted parameters -- such as those generated by Syzbot -- can result in a page/folio being inserted with a page index of ULONG_MAX, triggering the above problem. This resolves the issue by checking the ranges of 'vd_offset' and 'vd_vblocknr' in the nilfs_vdesc structure that determine the page index, thereby preventing the invalid page/folio insertions. Reported-by: syzbot+c37bed40868932d790e9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c37bed40868932d790e9 Fixes: 7942b919f732 ("nilfs2: ioctl operations") Cc: wuyankun Cc: stable@vger.kernel.org Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin --- fs/nilfs2/ioctl.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c index 0a43f1f956cb7..baa43a13b7a87 100644 --- a/fs/nilfs2/ioctl.c +++ b/fs/nilfs2/ioctl.c @@ -513,6 +513,7 @@ static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp, * Return: 0 on success, or one of the following negative error codes on * failure: * * %-EEXIST - Block conflict detected. + * * %-EINVAL - Invalid virtual block descriptor. * * %-EIO - I/O error. * * %-ENOENT - Requested block doesn't exist. * * %-ENOMEM - Insufficient memory available. @@ -522,15 +523,30 @@ static int nilfs_ioctl_move_inode_block(struct inode *inode, struct list_head *buffers) { struct buffer_head *bh; + __u64 limit_blkidx = (__u64)inode->i_sb->s_maxbytes >> inode->i_blkbits; int ret; - if (vdesc->vd_flags == 0) + /* + * vblocknr 0 is reserved as an invalid pointer. Also, limit_blkidx + * ensures that the page index converted from vd_vblocknr never + * overflows the page cache limit and respects the architecture's bmap + * key width. + */ + if (unlikely(vdesc->vd_vblocknr == 0 || + vdesc->vd_vblocknr >= limit_blkidx)) + return -EINVAL; + + if (vdesc->vd_flags == 0) { + if (unlikely(vdesc->vd_offset >= limit_blkidx)) + return -EINVAL; + ret = nilfs_gccache_submit_read_data( inode, vdesc->vd_offset, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh); - else + } else { ret = nilfs_gccache_submit_read_node( inode, vdesc->vd_blocknr, vdesc->vd_vblocknr, &bh); + } if (unlikely(ret < 0)) { if (ret == -ENOENT) -- 2.53.0