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 F20333793CA; Sat, 12 Sep 2026 17:08:39 +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=1789232921; cv=none; b=fouDaA6D+ttF0oOiF2qvcBmGnWwrBzN4NPiHOAURgxy4g5FkG7OkdUxHSIxdP/bHYqdApDu/TZzdNtMh1iHzIVnoQpcioY/9pp3+CXOUYWwh6cHmW2f9j5O4Z4IrkSWuhDpM2+v2kUQAPYptkoQ4lMyi9Lo1bp6CPxy0w9Fk2Vg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789232921; c=relaxed/simple; bh=qDDLO9TDoEz3Xds2B5BdzE5QpvyLTLgm/VPjW+Zo09Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K814OwxvIzzJyE3Vi06myDkkT9uiCh3xXZhIQr5CgStZCO3a3xCpLK04UQevEuJPGSm8vZ5PTsLiK2jyYszxUXuZHIrkdp9toOObbAqDXT2ayvUXu+50RbYBKokzwirjquXZ1fdqpaRiuiOe/3vVTrxuHeDFk9BwDQ4viw5rxgM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ghWEkYMT; 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="ghWEkYMT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01D761F000FF; Sat, 12 Sep 2026 17:08:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789232919; bh=rNw4Lj0emrYtgOAjtN5TEmV3HBjIFmh1xWHPyn165Aw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ghWEkYMT/evLjHtOUm9YJHO54Yab70KDEcLnzy8PWI9NKZ7p+45TY+RzEqO6UzGbw qeUPmzQpXj8eFZTk+zzLGzpINgeHAlRTkZyCHuIdKIH1abVcJv6JVnkANpPIMhyD/s PP2p7fQxJSfmzfHPpphpbSq6aak1WvHSjLlaRcWY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeff Layton , Chuck Lever Subject: [PATCH 5.15 108/935] SUNRPC: always drain cache_cleaner before destroying a cache_detail Date: Sat, 12 Sep 2026 08:52:18 +0200 Message-ID: <20260912065529.296159715@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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 @@ -410,10 +410,9 @@ 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);