From: Sujit Kautkar <sujitka@chromium.org>
To: Andy Gross <agross@kernel.org>, Ohad Ben-Cohen <ohad@wizery.com>
Cc: Sibi Sankar <sibis@codeaurora.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Stephen Boyd <swboyd@chromium.org>,
Sujit Kautkar <sujitka@google.com>,
Sujit Kautkar <sujitka@chromium.org>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-remoteproc@vger.kernel.org
Subject: [PATCH 1/2] rpmsg: glink: Fix use-after-free in qcom_glink_rpdev_release()
Date: Mon, 25 Oct 2021 16:24:59 -0700 [thread overview]
Message-ID: <20211025162452.1.Id19324ea36b4cf89faf98bf520bc6b6f01240433@changeid> (raw)
In-Reply-To: <20211025232500.1775231-1-sujitka@chromium.org>
From: Sujit Kautkar <sujitka@google.com>
qcom_glink_rpdev_release() sets channel->rpdev to NULL. However, with
debug enabled kernel, qcom_glink_rpdev_release() gets delayed due to
delayed kobject release and channel gets released by that time and
triggers below kernel warning. To avoid this use-after-free, add a
condition to checks if channel was already released.
| BUG: KASAN: use-after-free in qcom_glink_rpdev_release+0x54/0x70
| Write of size 8 at addr ffffffaba438e8d0 by task kworker/6:1/54
|
| CPU: 6 PID: 54 Comm: kworker/6:1 Not tainted 5.4.109-lockdep #16
| Hardware name: Google Lazor (rev3+) with KB Backlight (DT)
| Workqueue: events kobject_delayed_cleanup
| Call trace:
| dump_backtrace+0x0/0x284
| show_stack+0x20/0x2c
| dump_stack+0xd4/0x170
| print_address_description+0x3c/0x4a8
| __kasan_report+0x144/0x168
| kasan_report+0x10/0x18
| __asan_report_store8_noabort+0x1c/0x24
| qcom_glink_rpdev_release+0x54/0x70
| device_release+0x68/0x14c
| kobject_delayed_cleanup+0x158/0x2cc
| process_one_work+0x7cc/0x10a4
| worker_thread+0x80c/0xcec
| kthread+0x2a8/0x314
| ret_from_fork+0x10/0x18
Signed-off-by: Sujit Kautkar <sujitka@chromium.org>
---
drivers/rpmsg/qcom_glink_native.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index e1444fefdd1c0..cc3556a9385a9 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -270,6 +270,7 @@ static void qcom_glink_channel_release(struct kref *ref)
spin_unlock_irqrestore(&channel->intent_lock, flags);
kfree(channel->name);
+ channel = NULL;
kfree(channel);
}
@@ -1372,8 +1373,10 @@ static void qcom_glink_rpdev_release(struct device *dev)
{
struct rpmsg_device *rpdev = to_rpmsg_device(dev);
struct glink_channel *channel = to_glink_channel(rpdev->ept);
+ if (channel) {
+ channel->rpdev = NULL;
+ }
- channel->rpdev = NULL;
kfree(rpdev);
}
--
2.31.0
next prev parent reply other threads:[~2021-10-25 23:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 23:24 [PATCH 0/2] Fix two kernel warnings in glink driver Sujit Kautkar
2021-10-25 23:24 ` Sujit Kautkar [this message]
2021-10-25 23:25 ` [PATCH 2/2] rpmsg: glink: Update cdev add/del API in rpmsg_ctrldev_release_device() Sujit Kautkar
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