Re: [1/2] mwifiex: fix use-after-free for FW reinit errors

[Kalle Valo]

Brian Norris  wrote:
> If we fail to reinit the FW when resetting the device (in the
> synchronous version of mwifiex_init_hw_fw() -> mwifiex_fw_dpc()),
> mwifiex_fw_dpc() will tear down the interface and free up the adapter.
> But we don't actually check for all failure cases of mwifiex_fw_dpc(),
> so some of them fall through and dereference adapter->fw_done with a
> freed adapter, causing a use-after-free bug.
> 
> In any case, mwifiex_fw_dpc() will always signal FW completion -- in the
> error OR success case -- so at best, this was repeat work. Let's not do
> it.
> 
> Signed-off-by: Brian Norris 

2 patches applied to wireless-drivers-next.git, thanks.

ce8fad9a1f09 mwifiex: fix use-after-free for FW reinit errors
755b37c93a06 mwifiex: catch mwifiex_fw_dpc() errors properly in reset

-- 
https://patchwork.kernel.org/patch/9650725/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

[PATCH 1/2] mwifiex: fix use-after-free for FW reinit errors

[Brian Norris]

If we fail to reinit the FW when resetting the device (in the
synchronous version of mwifiex_init_hw_fw() -> mwifiex_fw_dpc()),
mwifiex_fw_dpc() will tear down the interface and free up the adapter.
But we don't actually check for all failure cases of mwifiex_fw_dpc(),
so some of them fall through and dereference adapter->fw_done with a
freed adapter, causing a use-after-free bug.

In any case, mwifiex_fw_dpc() will always signal FW completion -- in the
error OR success case -- so at best, this was repeat work. Let's not do
it.

Signed-off-by: Brian Norris 
---
 drivers/net/wireless/marvell/mwifiex/main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/main.c 
b/drivers/net/wireless/marvell/mwifiex/main.c
index 30f49944661f..98c83453ba5b 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.c
+++ b/drivers/net/wireless/marvell/mwifiex/main.c
@@ -1475,7 +1475,6 @@ mwifiex_reinit_sw(struct mwifiex_adapter *adapter)
}
mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
 
-   complete_all(adapter->fw_done);
return 0;
 
 err_init_fw:
-- 
2.12.2.564.g063fe858b8-goog