[PATCH 5.4 101/110] rsi: fix use-after-free on probe errors

Greg Kroah-Hartman
2020-01-30T18:50:39Z

From: Johan Hovold <johan@kernel.org>

commit 92aafe77123ab478e5f5095878856ab0424910da upstream.

The driver would fail to stop the command timer in most error paths,
something which specifically could lead to the timer being freed while
still active on I/O errors during probe.

Fix this by making sure that each function starting the timer also stops
it in all relevant error paths.

Reported-by: syzbot+1d1597a5aa3679c65b9f@syzkaller.appspotmail.com
Fixes: b78e91bcfb33 ("rsi: Add new firmware loading method")
Cc: stable <stable@vger.kernel.org> # 4.12
Cc: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Cc: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/rsi/rsi_91x_hal.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/net/wireless/rsi/rsi_91x_hal.c
+++ b/drivers/net/wireless/rsi/rsi_91x_hal.c
@@ -622,6 +622,7 @@ static int bl_cmd(struct rsi_hw *adapter
bl_start_cmd_timer(adapter, timeout);
status = bl_write_cmd(adapter, cmd, exp_resp, &regout_val);
if (status < 0) {
+ bl_stop_cmd_timer(adapter);
rsi_dbg(ERR_ZONE,
"%s: Command %s (%0x) writing failed..\n",
__func__, str, cmd);
@@ -737,10 +738,9 @@ static int ping_pong_write(struct rsi_hw
}

status = bl_cmd(adapter, cmd_req, cmd_resp, str);
- if (status) {
- bl_stop_cmd_timer(adapter);
+ if (status)
return status;
- }
+
return 0;
}

@@ -828,10 +828,9 @@ static int auto_fw_upgrade(struct rsi_hw

status = bl_cmd(adapter, EOF_REACHED, FW_LOADING_SUCCESSFUL,
"EOF_REACHED");
- if (status) {
- bl_stop_cmd_timer(adapter);
+ if (status)
return status;
- }
+
rsi_dbg(INFO_ZONE, "FW loading is done and FW is running..\n");
return 0;
}
@@ -849,6 +848,7 @@ static int rsi_hal_prepare_fwload(struct
&regout_val,
RSI_COMMON_REG_SIZE);
if (status < 0) {
+ bl_stop_cmd_timer(adapter);
rsi_dbg(ERR_ZONE,
"%s: REGOUT read failed\n", __func__);
return status;