[PATCH] net: wireless: b43: Avoid possible double calls to b43_one_core_detach()

From: Jia-Ju Bai
Date: Sat May 04 2019 - 05:10:55 EST


In b43_request_firmware(), when ieee80211_register_hw() fails,
b43_one_core_detach() is called. In b43_bcma_remove() and
b43_ssb_remove(), b43_one_core_detach() is called again. In this case,
null-pointer dereferences and double-free problems can occur when
the driver is removed.

To fix this bug, the call to b43_one_core_detach() in
b43_request_firmware() is deleted.

This bug is found by a runtime fuzzing tool named FIZZER written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/net/wireless/broadcom/b43/main.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index 74be3c809225..e666a472a0da 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -2610,18 +2610,13 @@ static void b43_request_firmware(struct work_struct *work)

err = ieee80211_register_hw(wl->hw);
if (err)
- goto err_one_core_detach;
+ goto out;
wl->hw_registered = true;
b43_leds_register(wl->current_dev);

/* Register HW RNG driver */
b43_rng_init(wl);

- goto out;
-
-err_one_core_detach:
- b43_one_core_detach(dev->dev);
-
out:
kfree(ctx);
}
--
2.17.0