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 AB77E281379; Mon, 5 May 2025 23:03:31 +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=1746486211; cv=none; b=OCg7vKiCJtr2WqjpUxrY7bh0vm9jVz1F4AyPJ71vB6me9zBMHxKpFF4G3tNVZEwA2nEGD0G8eXoJVrKJ/jKrV5ZByvWgEx9SN3Woa33VJBrqygRZqmRiwiZ/8In5wxKnEwv99lBxtqqdYByyx7fzCYXUJdwz7EUwrJUGrUHBw8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486211; c=relaxed/simple; bh=izhou5qxPFbb1SvbzdJaU6K5rcctrghYjKIyrQ0y4Q4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pVEbOOHcVzyNKHpoXLxTBRaIhqedbAVfPcsn2CxE92l9QmKAvthOgmr4cCHmukq5ffFnney+ssYHgWRbM/pTC9mwHRl5GXXAWqHqubrBz0ZVyNulJvP+itj7WNjOuxeM7aJLK5/vqqKJYvlFkTvEkxoIsu7ZXHJ/+U47jwofaJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pxG+Sb5X; 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="pxG+Sb5X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD4ACC4CEED; Mon, 5 May 2025 23:03:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486211; bh=izhou5qxPFbb1SvbzdJaU6K5rcctrghYjKIyrQ0y4Q4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pxG+Sb5XUtuCANQHVylDkQbkyih59j0Fv9CyZC+xa3z9eNgbHJdEY0DH2asa+oxUp jnwtH+x/KyxtUCFV0Hp7yVrUVoiKiIf9sPRQBnbPz9eVZMzn8JETqpNc46Dydvgh9T GNkN22facXTQw9WIwSiRqJ/fGLm1lidTnLZISl2xzUYMlZhgzJUuA8WJ7BXORfzKNp A4ZMfOJkx2ZZclnTrZWRi6u/71dHO8uTmesGBT05MlWI7EccH4cMU3phf8kLPkWP4X 4mW+2O8B80f4PFmRSJWkBuPfKctm92P/A0pHXyh7lcElx9t+jkqJ8YULBtnOY53U8i OwyyzeNGcOMeg== 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 6.6 209/294] kernfs: Acquire kernfs_rwsem in kernfs_get_parent_dentry(). Date: Mon, 5 May 2025 18:55:09 -0400 Message-Id: <20250505225634.2688578-209-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505225634.2688578-1-sashal@kernel.org> References: <20250505225634.2688578-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.89 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 c4bf26142eec9..5fda25dbbd256 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -147,7 +147,9 @@ 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