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 B37E13242BD; Fri, 4 Sep 2026 05:51:13 +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=1788501074; cv=none; b=aRg2/47J643yK76Pw/Zuu/pvUJuwN6YUyDqn7o91FNXlQUd2kOExQP6l+afL0WlDrKWT3hkvWqubYgJ7lf3oCnH2fFvivNPPrV0Y4eFBSaCa/UbUTMYq5nhOGThfxAMxSTpgh++CurSu2eCZ9ENc9+1rw7bGmCqCiLiPnXNlK9s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501074; c=relaxed/simple; bh=UZcTqViQCqxiZ7GF9e/ffwTrXOO3X54ZUXwKjuIvIfA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h+kWpqBuoJwbNSB3R7glIYE0GYcNIYXYCS1PLbaiUzzPs+kmq8sR7zjmQX5k7u2OzsUUNc2o8qqhnQ7Zv2j+Wlj+os9OLdBQXT3Pk0iNadeI8edk2aQCaBPzhAjp2aLv/VZv1aOt++NZP55FcOhA2OYzVk+pxjAsonfInvV5x9c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SlLNtHUs; 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="SlLNtHUs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C5E71F00A3D; Fri, 4 Sep 2026 05:51:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501073; bh=zQC5dQgqs/E43dDJtBxtrxNjqvF0zls8cHnZultKYKY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SlLNtHUs5NWZgEaDXftrffEtAp49qKZKnGHSZo+FCXrYUeovzKdAM3rwtkuXfAuJY NzhO85fBvbnRrIgOJcfCqMm3lL5zYG1YmCutwj0rqV+KODvXOU4aCKVmPKLJjlEOsM dY1GbWdH5vDKYj6Fykh3Oq79kiDQjG6rFIp/1G/Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeff Layton , Chuck Lever Subject: [PATCH 6.18 281/552] SUNRPC: always drain cache_cleaner before destroying a cache_detail Date: Fri, 4 Sep 2026 06:57:18 +0200 Message-ID: <20260904045756.334947185@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton commit f42d0fda0c67695db6bc704b04b7c10240805377 upstream. sunrpc_destroy_cache_detail() only cancels the global cache_cleaner delayed_work when cache_list is empty. During per-netns teardown cache_list is never empty because init_net's caches remain registered, so the cancel never fires. After unlink, the caller proceeds to cache_destroy_net() which kfrees the cache_detail while cache_clean() may still hold a dangling pointer to it. The result is a use-after-free: cache_dequeue() takes cd->queue_lock on freed memory, and cache_put() dereferences cd->cache_put as a function pointer from freed slab. Drop the list_empty guard so that cancel_delayed_work_sync() always runs, ensuring any in-flight cache_clean() completes before the cache_detail is freed. Re-arm the cleaner afterwards if other caches are still registered. Fixes: 820f9442e711 ("SUNRPC: split cache creation and PipeFS registration") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260526-cache_cleaner_vs_destroy_no_sync-v1-1-a707a6fcfd32@kernel.org Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/cache.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -423,10 +423,9 @@ void sunrpc_destroy_cache_detail(struct list_del_init(&cd->others); spin_unlock(&cd->hash_lock); spin_unlock(&cache_list_lock); - if (list_empty(&cache_list)) { - /* module must be being unloaded so its safe to kill the worker */ - cancel_delayed_work_sync(&cache_cleaner); - } + cancel_delayed_work_sync(&cache_cleaner); + if (!list_empty(&cache_list)) + queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0); } EXPORT_SYMBOL_GPL(sunrpc_destroy_cache_detail);