4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Fedor Pchelkin pchelkin@ispras.ru
[ Upstream commit 454994cfa9e4c18b6df9f78b60db8eadc20a6c25 ]
If ath9k_wmi_cmd() has exited with a timeout, it is possible that during next ath9k_wmi_cmd() call the wmi_rsp callback for previous wmi command writes to new wmi->cmd_rsp_buf and makes a completion. This results in an invalid ath9k_wmi_cmd() return value.
Move the replacement of WMI command response buffer and length under wmi_lock. Note that last_seq_id value is updated there, too.
Thus, the buffer cannot be written to by a belated wmi_rsp callback because that path is properly rejected by the last_seq_id check.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: fb9987d0f748 ("ath9k_htc: Support for AR9271 chipset.") Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Acked-by: Toke Høiland-Jørgensen toke@toke.dk Signed-off-by: Kalle Valo quic_kvalo@quicinc.com Link: https://lore.kernel.org/r/20230425192607.18015-2-pchelkin@ispras.ru Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/ath/ath9k/wmi.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c index 7b4e922181190..e0ecd2e867477 100644 --- a/drivers/net/wireless/ath/ath9k/wmi.c +++ b/drivers/net/wireless/ath/ath9k/wmi.c @@ -279,7 +279,8 @@ int ath9k_wmi_connect(struct htc_target *htc, struct wmi *wmi,
static int ath9k_wmi_cmd_issue(struct wmi *wmi, struct sk_buff *skb, - enum wmi_cmd_id cmd, u16 len) + enum wmi_cmd_id cmd, u16 len, + u8 *rsp_buf, u32 rsp_len) { struct wmi_cmd_hdr *hdr; unsigned long flags; @@ -289,6 +290,11 @@ static int ath9k_wmi_cmd_issue(struct wmi *wmi, hdr->seq_no = cpu_to_be16(++wmi->tx_seq_id);
spin_lock_irqsave(&wmi->wmi_lock, flags); + + /* record the rsp buffer and length */ + wmi->cmd_rsp_buf = rsp_buf; + wmi->cmd_rsp_len = rsp_len; + wmi->last_seq_id = wmi->tx_seq_id; spin_unlock_irqrestore(&wmi->wmi_lock, flags);
@@ -329,11 +335,7 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id, goto out; }
- /* record the rsp buffer and length */ - wmi->cmd_rsp_buf = rsp_buf; - wmi->cmd_rsp_len = rsp_len; - - ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len); + ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len, rsp_buf, rsp_len); if (ret) goto out;