From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:37976 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752669AbeBBRJb (ORCPT ); Fri, 2 Feb 2018 12:09:31 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shaohua Li , David Disseldorp , Jens Axboe , Sasha Levin Subject: [PATCH 4.14 056/156] null_blk: fix dev->badblocks leak Date: Fri, 2 Feb 2018 17:57:17 +0100 Message-Id: <20180202140842.829885141@linuxfoundation.org> In-Reply-To: <20180202140840.242829545@linuxfoundation.org> References: <20180202140840.242829545@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Disseldorp [ Upstream commit 1addb798e93893d33c8dfab743cd44f09fd7719a ] null_alloc_dev() allocates memory for dev->badblocks, but cleanup currently only occurs in the configfs release codepath, missing a number of other places. This bug was found running the blktests block/010 test, alongside kmemleak: rapido1:/blktests# ./check block/010 ... rapido1:/blktests# echo scan > /sys/kernel/debug/kmemleak [ 306.966708] kmemleak: 32 new suspected memory leaks (see /sys/kernel/debug/kmemleak) rapido1:/blktests# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88001f86d000 (size 4096): comm "modprobe", pid 231, jiffies 4294892415 (age 318.252s) hex dump (first 32 bytes): 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 00 ................ backtrace: [] kmemleak_alloc+0x49/0xa0 [] kmem_cache_alloc+0x9f/0xe0 [] badblocks_init+0x2f/0x60 [] 0xffffffffa0019fae [] nullb_device_badblocks_store+0x63/0x130 [null_blk] [] do_one_initcall+0x3d/0x170 [] do_init_module+0x56/0x1e9 [] load_module+0x1c47/0x26a0 [] SyS_finit_module+0xa9/0xd0 [] entry_SYSCALL_64_fastpath+0x13/0x94 Fixes: 2f54a613c942 ("nullb: badbblocks support") Reviewed-by: Shaohua Li Signed-off-by: David Disseldorp Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/block/null_blk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -467,7 +467,6 @@ static void nullb_device_release(struct { struct nullb_device *dev = to_nullb_device(item); - badblocks_exit(&dev->badblocks); null_free_device_storage(dev, false); null_free_dev(dev); } @@ -578,6 +577,10 @@ static struct nullb_device *null_alloc_d static void null_free_dev(struct nullb_device *dev) { + if (!dev) + return; + + badblocks_exit(&dev->badblocks); kfree(dev); }