[PATCH 4.14 066/191] ath6kl: wmi: prevent a shift wrapping bug in ath6kl_wmi_delete_pstream_cmd()

Greg Kroah-Hartman
2020-10-27T18:11:32Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 6a950755cec1a90ddaaff3e4acb5333617441c32 ]

The "tsid" is a user controlled u8 which comes from debugfs. Values
more than 15 are invalid because "active_tsids" is a 16 bit variable.
If the value of "tsid" is more than 31 then that leads to a shift
wrapping bug.

Fixes: 8fffd9e5ec9e ("ath6kl: Implement support for QOS-enable and QOS-disable from userspace")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200918142732.GA909725@mwanda
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath6kl/wmi.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index d79c2bccf5822..f80f1757b58fc 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -2648,6 +2648,11 @@ int ath6kl_wmi_delete_pstream_cmd(struct wmi *wmi, u8 if_idx, u8 traffic_class,
return -EINVAL;
}

+ if (tsid >= 16) {
+ ath6kl_err("invalid tsid: %d\n", tsid);
+ return -EINVAL;
+ }
+
skb = ath6kl_wmi_get_new_buf(sizeof(*cmd));
if (!skb)
return -ENOMEM;
--
2.25.1