linux-kernel - [PATCH AUTOSEL 5.4 3/9] memstick: r592: Fix UAF bug in r592

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

Message-Id: <20230501030611.3255082-3-sashal@kernel.org>
Date:   Sun, 30 Apr 2023 23:06:03 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Zheng Wang <zyytlz.wz@....com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Sasha Levin <sashal@...nel.org>, maximlevitsky@...il.com,
        oakad@...oo.com, linux-mmc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 3/9] memstick: r592: Fix UAF bug in r592_remove due to race condition

From: Zheng Wang <zyytlz.wz@....com>

[ Upstream commit 63264422785021704c39b38f65a78ab9e4a186d7 ]

In r592_probe, dev->detect_timer was bound with r592_detect_timer.
In r592_irq function, the timer function will be invoked by mod_timer.

If we remove the module which will call hantro_release to make cleanup,
there may be a unfinished work. The possible sequence is as follows,
which will cause a typical UAF bug.

Fix it by canceling the work before cleanup in r592_remove.

CPU0                  CPU1

                    |r592_detect_timer
r592_remove         |
  memstick_free_host|
  put_device;       |
  kfree(host);      |
                    |
                    | queue_work
                    |   &host->media_checker //use

Signed-off-by: Zheng Wang <zyytlz.wz@....com>
Link: https://lore.kernel.org/r/20230307164338.1246287-1-zyytlz.wz@163.com
Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/memstick/host/r592.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/memstick/host/r592.c b/drivers/memstick/host/r592.c
index eaa2a94d18be4..dd06c18495eb6 100644
--- a/drivers/memstick/host/r592.c
+++ b/drivers/memstick/host/r592.c
@@ -828,7 +828,7 @@ static void r592_remove(struct pci_dev *pdev)
 	/* Stop the processing thread.
 	That ensures that we won't take any more requests */
 	kthread_stop(dev->io_thread);
-
+	del_timer_sync(&dev->detect_timer);
 	r592_enable_device(dev, false);
 
 	while (!error && dev->req) {
-- 
2.39.2