From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga06-in.huawei.com (szxga06-in.huawei.com [45.249.212.32]) (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 5CB4D1448FE for ; Tue, 27 Feb 2024 14:14:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709043266; cv=none; b=aYmcaZwl7ghffTsdB18MKIvT1Zwhh/ME+j3xLtu2Z1VwMpOhkpf53qh7k0JqSpiYuFiOjuf9JrxF8YRXJ4AJLuKy3EvzCeDjbBABY0iOyLBeB4iFw7/exEQQdJ/DnNzOp+lXAq887SNRlkdxzwM1l3RqCik1oAqcOk5KvCTxC7k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709043266; c=relaxed/simple; bh=KIHT+zbONEULVaHBjxI9h4H8JhMH4JkvomTmsYEXKdc=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Mk4GFuzR2XPvs9IND9WsOaTeU3MjlMZXAZHy8X7XHLvkBRNK0rT3RLd2OQuFXOqtWPXQVq0OvsH1INrygypy91R88oKnNCTz6J3RFkAw7H6J+Gw1S6LtMI6Tuk4Z+sm5wLepF4PvudUUAFmCQ9XscX3rrx0iU1IF5ECfVISf6AU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4Tkfbr0zZDzqhtF; Tue, 27 Feb 2024 22:13:44 +0800 (CST) Received: from dggpeml500021.china.huawei.com (unknown [7.185.36.21]) by mail.maildlp.com (Postfix) with ESMTPS id EE70E140419; Tue, 27 Feb 2024 22:14:20 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 27 Feb 2024 22:14:20 +0800 From: Baokun Li To: CC: , , , , , , David Howells , Jingbo Xu , Jeff Layton , Christian Brauner Subject: [PATCH 4.19/5.4/5.10/5.15] cachefiles: fix memory leak in cachefiles_add_cache() Date: Tue, 27 Feb 2024 22:16:06 +0800 Message-ID: <20240227141606.1047435-1-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500021.china.huawei.com (7.185.36.21) commit e21a2f17566cbd64926fb8f16323972f7a064444 upstream. The following memory leak was reported after unbinding /dev/cachefiles: ================================================================== unreferenced object 0xffff9b674176e3c0 (size 192): comm "cachefilesd2", pid 680, jiffies 4294881224 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc ea38a44b): [] kmem_cache_alloc+0x2d5/0x370 [] prepare_creds+0x26/0x2e0 [] cachefiles_determine_cache_security+0x1f/0x120 [] cachefiles_add_cache+0x13c/0x3a0 [] cachefiles_daemon_write+0x146/0x1c0 [] vfs_write+0xcb/0x520 [] ksys_write+0x69/0xf0 [] do_syscall_64+0x72/0x140 [] entry_SYSCALL_64_after_hwframe+0x6e/0x76 ================================================================== Put the reference count of cache_cred in cachefiles_daemon_unbind() to fix the problem. And also put cache_cred in cachefiles_add_cache() error branch to avoid memory leaks. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") CC: stable@vger.kernel.org Signed-off-by: Baokun Li Link: https://lore.kernel.org/r/20240217081431.796809-1-libaokun1@huawei.com Acked-by: David Howells Reviewed-by: Jingbo Xu Reviewed-by: Jeff Layton Signed-off-by: Christian Brauner Signed-off-by: Baokun Li --- fs/cachefiles/bind.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c index 4a717d400807..9b34d46bf8ee 100644 --- a/fs/cachefiles/bind.c +++ b/fs/cachefiles/bind.c @@ -249,6 +249,8 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache) kmem_cache_free(cachefiles_object_jar, fsdef); error_root_object: cachefiles_end_secure(cache, saved_cred); + put_cred(cache->cache_cred); + cache->cache_cred = NULL; pr_err("Failed to register: %d\n", ret); return ret; } @@ -269,6 +271,7 @@ void cachefiles_daemon_unbind(struct cachefiles_cache *cache) dput(cache->graveyard); mntput(cache->mnt); + put_cred(cache->cache_cred); kfree(cache->rootdirname); kfree(cache->secctx); -- 2.31.1