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 C5D622749F0; Mon, 5 May 2025 22:51:20 +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=1746485480; cv=none; b=lf3stPeEZxlrPso3T//F3TKuwmCNY9o4CGkr3yfm/qO/k02bNCouw/CppTzMa4HdD5CPPaM8yJBqo8bzuoS5bXdxnJkJxy51dFA22i3Rs/gaNwmilOqTxglIekBwUen5yWKn5r+N/nrKq9DM7VhZ+6ZcVzWKEyQA900WUYUG2Nk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485480; c=relaxed/simple; bh=lFmRf0UqXzAD/H+cDJ45OmX59Qe26LwGgupNtdazpJ0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LnFM5b7CVE/oBLoE8d8ytVh842RMKG2DGw90b6rdC05NfSKUzi86ZEUsS74bm55T4zQPhLIMRIjzwD/YqE4lcDHMXv4UvwP9Uy9PbaPIkUXIeFxtyR1DLfTNCJXqyrNxCip8O8z6Px8onkibVmb/WF4IfPHb8aWJh5BPPvfRm5g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PKJMoRul; 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="PKJMoRul" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 928EDC4CEE4; Mon, 5 May 2025 22:51:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746485480; bh=lFmRf0UqXzAD/H+cDJ45OmX59Qe26LwGgupNtdazpJ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PKJMoRulYn9MPLX0kzFLep1MuNVfyDWb4/5sCYHFX0mYehFW4Pu2HrbfDkf4LsJNz W3Syo1BGukpYzUrglSIa/7/yWpg343IWZ4LvyGeEkpTwyztHP3RJykWiadXeAWWAJw ngAiEA+AkA2Hm9zKSJgvc1VvE8b/0HfDoHVlHzp9hW4gNCJyKRmkR1g6HHSHZ9aZj0 Bn3/A3+iIe9T7ei9JG6hAO3JPFlxoK77tFMarovzskQl5LcrI3rXIZ7ZbSLTRdr9Ik BpMQ0CYHQK2U2tbzBid74zcG5Ek3gYRdERRLrqFciCvjLKmSbRVUTgWXVD5mfQdnVN Y7Ry0LWfROdhg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sebastian Andrzej Siewior , Tejun Heo , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 6.12 337/486] kernfs: Acquire kernfs_rwsem in kernfs_get_parent_dentry(). Date: Mon, 5 May 2025 18:36:53 -0400 Message-Id: <20250505223922.2682012-337-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505223922.2682012-1-sashal@kernel.org> References: <20250505223922.2682012-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.26 Content-Transfer-Encoding: 8bit From: Sebastian Andrzej Siewior [ Upstream commit 122ab92dee80582c39740609a627198dd5b6b595 ] kernfs_get_parent_dentry() passes kernfs_node::parent to kernfs_get_inode(). Acquire kernfs_root::kernfs_rwsem to ensure kernfs_node::parent isn't replaced during the operation. Acked-by: Tejun Heo Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250213145023.2820193-3-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- fs/kernfs/mount.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 0f6379ae258d1..4a0ff08d589ca 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -145,7 +145,9 @@ static struct dentry *kernfs_fh_to_parent(struct super_block *sb, static struct dentry *kernfs_get_parent_dentry(struct dentry *child) { struct kernfs_node *kn = kernfs_dentry_node(child); + struct kernfs_root *root = kernfs_root(kn); + guard(rwsem_read)(&root->kernfs_rwsem); return d_obtain_alias(kernfs_get_inode(child->d_sb, kn->parent)); } -- 2.39.5