linux-kernel - [PATCH v2] ubi: fastmap: Don't produce the initial anchor PEB when fastmap is disabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20200602112410.660785-1-chengzhihao1@huawei.com>
Date:   Tue, 2 Jun 2020 19:24:10 +0800
From:   Zhihao Cheng <chengzhihao1@...wei.com>
To:     <linux-mtd@...ts.infradead.org>, <linux-kernel@...r.kernel.org>
CC:     <richard@....at>, <s.hauer@...gutronix.de>, <yi.zhang@...wei.com>
Subject: [PATCH v2] ubi: fastmap: Don't produce the initial anchor PEB when fastmap is disabled

Following process triggers a memleak caused by forgetting to release the
initial anchor PEB (CONFIG_MTD_UBI_FASTMAP is disabled):
1. attach -> __erase_worker -> produce the initial anchor PEB
2. detach -> ubi_fastmap_close (Do nothing, it should have released the
   initial anchor PEB)

Don't produce the initial anchor PEB in __erase_worker() when fastmap
is disabled.

Signed-off-by: Zhihao Cheng <chengzhihao1@...wei.com>
Suggested-by: Sascha Hauer <s.hauer@...gutronix.de>
Fixes: f9c34bb529975fe ("ubi: Fix producing anchor PEBs")
Reported-by: syzbot+d9aab50b1154e3d163f5@...kaller.appspotmail.com
---
 drivers/mtd/ubi/wl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 5146cce5fe32..f88486ccf5d5 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1079,7 +1079,8 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk)
 	if (!err) {
 		spin_lock(&ubi->wl_lock);
 
-		if (!ubi->fm_anchor && e->pnum < UBI_FM_MAX_START) {
+		if (!ubi->fm_disabled && !ubi->fm_anchor &&
+		    e->pnum < UBI_FM_MAX_START) {
 			ubi->fm_anchor = e;
 			ubi->fm_do_produce_anchor = 0;
 		} else {
-- 
2.25.4