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From: Zenghui Yu <yuzenghui@huawei.com>
To: <linux-wireless@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <zajec5@gmail.com>, <kvalo@codeaurora.org>, <hauke@hauke-m.de>,
	<linville@tuxdriver.com>, <wanghaibin.wang@huawei.com>,
	Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH 1/2] bcma: Fix memory leak for internally-handled cores
Date: Tue, 27 Jul 2021 10:52:31 +0800	[thread overview]
Message-ID: <20210727025232.663-2-yuzenghui@huawei.com> (raw)
In-Reply-To: <20210727025232.663-1-yuzenghui@huawei.com>

kmemleak reported that dev_name() of internally-handled cores were leaked
on driver unbinding. Let's use device_initialize() to take refcounts for
them and put_device() to properly free the related stuff.

While looking at it, there's another potential issue for those which should
be *registered* into driver core. If device_register() failed, we put
device once and freed bcma_device structures. In bcma_unregister_cores(),
they're treated as unregistered and we hit both UAF and double-free. That
smells not good and has also been fixed now.

Fixes: ab54bc8460b5 ("bcma: fill core details for every device")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
 drivers/bcma/main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
index 6535614a7dc1..1df2b5801c3b 100644
--- a/drivers/bcma/main.c
+++ b/drivers/bcma/main.c
@@ -236,6 +236,7 @@ EXPORT_SYMBOL(bcma_core_irq);
 
 void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core)
 {
+	device_initialize(&core->dev);
 	core->dev.release = bcma_release_core_dev;
 	core->dev.bus = &bcma_bus_type;
 	dev_set_name(&core->dev, "bcma%d:%d", bus->num, core->core_index);
@@ -277,11 +278,10 @@ static void bcma_register_core(struct bcma_bus *bus, struct bcma_device *core)
 {
 	int err;
 
-	err = device_register(&core->dev);
+	err = device_add(&core->dev);
 	if (err) {
 		bcma_err(bus, "Could not register dev for core 0x%03X\n",
 			 core->id.id);
-		put_device(&core->dev);
 		return;
 	}
 	core->dev_registered = true;
@@ -372,7 +372,7 @@ void bcma_unregister_cores(struct bcma_bus *bus)
 	/* Now noone uses internally-handled cores, we can free them */
 	list_for_each_entry_safe(core, tmp, &bus->cores, list) {
 		list_del(&core->list);
-		kfree(core);
+		put_device(&core->dev);
 	}
 }
 
-- 
2.19.1


  reply	other threads:[~2021-07-27  2:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-27  2:52 two small bcma patches Zenghui Yu
2021-07-27  2:52 ` Zenghui Yu [this message]
2021-08-21  3:28   ` [PATCH 1/2] bcma: Fix memory leak for internally-handled cores Zenghui Yu
2021-08-21 10:05     ` Kalle Valo
2021-08-23  3:56       ` Zenghui Yu
2021-08-29 11:45   ` Kalle Valo
2021-07-27  2:52 ` [PATCH 2/2] bcma: Drop the unused parameter of bcma_scan_read32() Zenghui Yu

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