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 7A6452D113E; Mon, 5 May 2025 22:51:21 +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=1746485481; cv=none; b=ZFVuDEn2H4Hf96jegDcu34z7kNRVrHGwQ8o3N5r0l8nQFvij7OrPVBnmM+cBGnUuvuBZK1YEVgUOmzIvmLWhiWEXQIdutMTF9s+Sy4ovffu7OJCkcuPnBOyBBbN+VdgBKnEY9hcEUAgXHdyqRTjX4nvqm6KGjL9Hpg05V35zeNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485481; c=relaxed/simple; bh=EYtw+AqDkKNk3Q+svkTmH4GW2t5HIn0ZPOM17SE5M+I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dAvW52bpPylkcb3Z2z7NIrZtDp7p/idfTAKMOQY7V443etx9LimNO/aHGBt3n2RM/nNpKDul4pZLMY+jZ9mdHrJdU+4ufv6xnyf1fObUgSei+FBjt9AyXWRBx8Q8huSIuSXN9j5Vcr8KjtL+hTe+/cVZGzZxgOkzyo/YNqTNJ2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QB3eephT; 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="QB3eephT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5589C4CEED; Mon, 5 May 2025 22:51:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746485481; bh=EYtw+AqDkKNk3Q+svkTmH4GW2t5HIn0ZPOM17SE5M+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QB3eephTGMUruI0WwtSsGzDNodf7ljwwdQParJO2bx9efWlHumfzIYLTlt2q+NqFx M+YbZf9CsQzmFv5z8S6lWg0jsOlVIyNeS8Nv3dT1DpMpkp6RjGTP6y6MQuyO938v2t eioluhzi5GP3NFMezqrlq875tjsBmJFzRTyL6fYnZFg18S5LZdO+SZzsxRj6huJsiA NmR//l53IH/pLnXehoNmusLn5ZLNxex9gly/KoyPR/UdOu81xqItm6qUyiVkuQMiHc xnN/Rj5ojXfnkgHMAmTeb6zyQHRN26EYJC+z9LHkUiSOEgGe8PEw2O/Dm4pqJhkThH De3a5eVrSAD3w== 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 6.12 338/486] kernfs: Acquire kernfs_rwsem in kernfs_notify_workfn(). Date: Mon, 5 May 2025 18:36:54 -0400 Message-Id: <20250505223922.2682012-338-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 400188ae361a9d9a72a47a6cedaf2d2efcc84aa8 ] kernfs_notify_workfn() dereferences kernfs_node::name and passes it later to fsnotify(). If the node is renamed then the previously observed name pointer becomes invalid. Acquire kernfs_root::kernfs_rwsem to block renames of the node. Acked-by: Tejun Heo Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250213145023.2820193-2-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- fs/kernfs/file.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8502ef68459b9..165d8e37976ba 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -911,6 +911,7 @@ static void kernfs_notify_workfn(struct work_struct *work) /* kick fsnotify */ down_read(&root->kernfs_supers_rwsem); + down_read(&root->kernfs_rwsem); list_for_each_entry(info, &kernfs_root(kn)->supers, node) { struct kernfs_node *parent; struct inode *p_inode = NULL; @@ -947,6 +948,7 @@ static void kernfs_notify_workfn(struct work_struct *work) iput(inode); } + up_read(&root->kernfs_rwsem); up_read(&root->kernfs_supers_rwsem); kernfs_put(kn); goto repeat; -- 2.39.5