[PATCH 5.13 250/300] bcma: Fix memory leak for internally-handled cores

Greg Kroah-Hartman
2021-09-13T14:14:53Z

From: Zenghui Yu <yuzenghui@huawei.com>

[ Upstream commit b63aed3ff195130fef12e0af590f4838cf0201d8 ]

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>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210727025232.663-2-yuzenghui@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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);
}
}

--
2.30.2