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 C592628137B; Mon, 5 May 2025 23:03:32 +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=1746486212; cv=none; b=UprO3Ay0M6mD06ljGUjStAXZwWItcY0O/V4DX3VmEbBKDdAkK1/CqcNNAQy1YMk0/n5hqUQ1kpn0/zcUBKD38hfZ0ak2hCXl9DHe6CtQoTbo/LYLVcCqmi1O7a0RclhLLGFmJtCi18jqO34NzYADskO9AygrEulSEcXBun5R4Dc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486212; c=relaxed/simple; bh=6RLmdhexPakcH2SycFVi5S8OZcX659nMSVKrz0xcr9o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pZtJVAUjym/GH95cxfHYTazNsYwI3YKGvsEhIzpd/E3qNorWfgWQECtb/gCAK5UtNJPq3H2p/YREdN4xORwETx4yZEbpQJNDbPMnocDOShr5/VLjGKWybgmnuSdyot8VRbjUR+Hyk2E9BTMm1NbqGEVhAzZxCo5DtxwpWtE8MkI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GyFmGbu4; 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="GyFmGbu4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC9DCC4CEE4; Mon, 5 May 2025 23:03:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486212; bh=6RLmdhexPakcH2SycFVi5S8OZcX659nMSVKrz0xcr9o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GyFmGbu42FUivSx+B1Uxn1nTRYFTP2ecKNKwT+YnrO4TaXXu08Mwot1ItFBHe68dP H4DMYNJd9LBGUIefH4pvTj6CAw2+qlcHm4hoEDWy7XBA8rkrJWEx8GK5j3adUM89GU c1oR7NzuW45xJvdr0RhZ560Tim9f6AmosUoSpQ/BFOgaylp4I4RTV/T8OZRMeMe9tr UXwIKEGA4xBAp8ZTrVLxP3FUA/blXmTICWb+Cunpwv23zJlZaXNwhtmLkHTRljTP/V cA+3U+MCSYWbyAIKBY1BFXPMT2dvv4GrGHM6SfyvFwaUkMsSoWuuEzzzSM6ILEK31V fxu4/6Ca43rIg== 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 6.6 210/294] kernfs: Acquire kernfs_rwsem in kernfs_notify_workfn(). Date: Mon, 5 May 2025 18:55:10 -0400 Message-Id: <20250505225634.2688578-210-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 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 332d08d2fe0d5..501502cd5194e 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -926,6 +926,7 @@ 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; @@ -962,6 +963,7 @@ 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