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 B7209384223; Thu, 30 Jul 2026 15:53:01 +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=1785426782; cv=none; b=H1ME99p8yIERINOqX3q+VxkiqDnMZFKkHpX3RSTImMEWMbbDX7Yceex08ZYXg6oBYyCwplOpGJQ8obsB3L19LNT6F2uFbip2zGHXy1yONM3HPf3C2/sqMnEii/Lbgk25oJ7E5rHtptNsDK6YaS3tf44jNETnbmdIdKl0mv+lk34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785426782; c=relaxed/simple; bh=MQPDM42gjWMEOdLjZD6G8mbg+uAKGFTbTSGoLn+tZSw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=RS5TmFTFS7LhwPGYDXwt/+SLjvCcJBG6QuQmg/PiRS9Mx02m5P672LWTh+qNyJx87VTJMFznJBeGFCuzGk9+fq4dDy9QPXiK1dfrQnU9IWreRDhNxIR1Tz8WRWiQzV1w9d9qxCAwCi9h+7lVQXESCpZzY3S17yTupbLjOu2z1dU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MB8FUY83; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MB8FUY83" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEB5B1F000E9; Thu, 30 Jul 2026 15:53:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785426781; bh=Bq+7d2g2w4KKhSf+aiOHKf/47K/3LPo7f2QNqDhXFkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MB8FUY83M2LHLwWxAHYDRCg5c65SU433hmxgV+zihkqtBn+/1bKrm/lmxoIsi0wyT NGb9tlMyzTMWflo1X29ENIbuAzgghYBqeJ8ZnMyLys085mEIFPa/zxLf7X+o8maC0A 58SO17mDW00eQUb8zUB4FMf1bOFD/QrjDB5HkpEs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Souvik Banerjee , Amir Goldstein , Miklos Szeredi , "Christian Brauner (Amutable)" , Sasha Levin Subject: [PATCH 6.12 540/602] ovl: use linked upper dentry in copy-up tmpfile Date: Thu, 30 Jul 2026 16:15:32 +0200 Message-ID: <20260730141447.373272789@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141435.976815864@linuxfoundation.org> References: <20260730141435.976815864@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Souvik Banerjee [ Upstream commit e348eecd4d8fa8d18a5157ff59f7be1dc59c5928 ] ovl_copy_up_tmpfile() stores the disconnected O_TMPFILE dentry as the overlay's upper dentry reference via ovl_inode_update(). vfs_tmpfile() allocated this dentry via d_alloc(parentpath->dentry, &slash_name), so d_name is "/" and d_parent is c->workdir. Local upper filesystems (ext4, btrfs, xfs, ...) immediately rename it to "#" via d_mark_tmpfile() inside their ->tmpfile() op; FUSE and virtiofs do not, so both fields stay that way. Neither identifies the destination directory and filename where ovl_do_link() actually linked the file. When the upper filesystem implements ->d_revalidate() (e.g. FUSE or virtiofs), ovl_revalidate_real() calls it with the dentry's parent inode and a snapshot of d_name. The server tries to look up "/" inside c->workdir, fails, and overlayfs reports -ESTALE. This causes persistent ESTALE errors for any file that was copied up via the tmpfile path, breaking dpkg, apt, and other tools that do rename-over-existing on overlayfs with a FUSE/virtiofs upper. Before commit 6b52243f633e ("ovl: fold copy-up helpers into callers"), the tmpfile copy-up path used a dedicated helper ovl_link_tmpfile() that captured the linked destination dentry returned by ovl_do_link(): err = ovl_do_link(temp, udir, upper); ... if (!err) *newdentry = dget(upper); and published it via ovl_inode_update(d_inode(c->dentry), newdentry). The fold inlined ovl_do_link() into ovl_copy_up_tmpfile() but dropped the dget(upper) capture, and rewrote the publish line as ovl_inode_update(d_inode(c->dentry), dget(temp)) — where temp is the disconnected O_TMPFILE dentry. Fix by keeping a reference to the linked destination dentry after ovl_do_link() succeeds, and publishing that dentry at the existing ovl_inode_update() call site. The non-tmpfile/workdir path continues to publish the renamed temporary dentry. Reproducer: - Mount overlayfs with virtiofs (or a FUSE fs whose server advertises FUSE_TMPFILE) as upper - Run: dpkg -i - Observe: "error installing new file '...': Stale file handle" Fixes: 6b52243f633e ("ovl: fold copy-up helpers into callers") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Souvik Banerjee Link: https://patch.msgid.link/20260501232735.2610824-1-souvik@amlalabs.com Reviewed-by: Amir Goldstein Reviewed-by: Miklos Szeredi Signed-off-by: Christian Brauner (Amutable) [ adapted scoped credential and creation helpers to explicit credential, locking, lookup, and cleanup handling ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -864,7 +864,7 @@ static int ovl_copy_up_tmpfile(struct ov { struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct inode *udir = d_inode(c->destdir); - struct dentry *temp, *upper; + struct dentry *temp, *upper, *newdentry = NULL; struct file *tmpfile; struct ovl_cu_creds cc; int err; @@ -901,6 +901,14 @@ static int ovl_copy_up_tmpfile(struct ov err = PTR_ERR(upper); if (!IS_ERR(upper)) { err = ovl_do_link(ofs, temp, udir, upper); + if (!err) { + /* + * Record the linked dentry -- not the disconnected + * O_TMPFILE dentry -- so that ->d_revalidate() on + * the upper fs sees the real parent/name. + */ + newdentry = dget(upper); + } dput(upper); } inode_unlock(udir); @@ -916,7 +924,7 @@ static int ovl_copy_up_tmpfile(struct ov if (!c->metacopy) ovl_set_upperdata(d_inode(c->dentry)); - ovl_inode_update(d_inode(c->dentry), dget(temp)); + ovl_inode_update(d_inode(c->dentry), newdentry); out: ovl_end_write(c->dentry);