[PATCH] Fix a double free bug in rsi_91x_deinit

From: Hui Peng
Date: Mon Aug 19 2019 - 18:02:46 EST


`dev` (struct rsi_91x_usbdev *) field of adapter
(struct rsi_91x_usbdev *) is allocated and initialized in
`rsi_init_usb_interface`. If any error is detected in information
read from the device side, `rsi_init_usb_interface` will be
freed. However, in the higher level error handling code in
`rsi_probe`, if error is detected, `rsi_91x_deinit` is called
again, in which `dev` will be freed again, resulting double free.

This patch fixes the double free by removing the free operation on
`dev` in `rsi_init_usb_interface`, because `rsi_91x_deinit` is also
used in `rsi_disconnect`, in that code path, the `dev` field is not
(and thus needs to be) freed.

This bug was found in v4.19, but is also present in the latest version
of kernel.

Reported-by: Hui Peng <benquike@xxxxxxxxx>
Reported-by: Mathias Payer <mathias.payer@xxxxxxxxxxxxx>
Signed-off-by: Hui Peng <benquike@xxxxxxxxx>
---
drivers/net/wireless/rsi/rsi_91x_usb.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index c0a163e40402..ac917227f708 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -640,7 +640,6 @@ static int rsi_init_usb_interface(struct rsi_hw *adapter,
kfree(rsi_dev->tx_buffer);

fail_eps:
- kfree(rsi_dev);

return status;
}
--
2.22.1