[PATCH 3.16 25/99] brcmfmac: abort and release host after error

From: Ben Hutchings
Date: Wed May 20 2020 - 10:26:39 EST


3.16.84-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Guenter Roeck <linux@xxxxxxxxxxxx>

commit 863844ee3bd38219c88e82966d1df36a77716f3e upstream.

With commit 216b44000ada ("brcmfmac: Fix use after free in
brcmf_sdio_readframes()") applied, we see locking timeouts in
brcmf_sdio_watchdog_thread().

brcmfmac: brcmf_escan_timeout: timer expired
INFO: task brcmf_wdog/mmc1:621 blocked for more than 120 seconds.
Not tainted 4.19.94-07984-g24ff99a0f713 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
brcmf_wdog/mmc1 D 0 621 2 0x00000000 last_sleep: 2440793077. last_runnable: 2440766827
[<c0aa1e60>] (__schedule) from [<c0aa2100>] (schedule+0x98/0xc4)
[<c0aa2100>] (schedule) from [<c0853830>] (__mmc_claim_host+0x154/0x274)
[<c0853830>] (__mmc_claim_host) from [<bf10c5b8>] (brcmf_sdio_watchdog_thread+0x1b0/0x1f8 [brcmfmac])
[<bf10c5b8>] (brcmf_sdio_watchdog_thread [brcmfmac]) from [<c02570b8>] (kthread+0x178/0x180)

In addition to restarting or exiting the loop, it is also necessary to
abort the command and to release the host.

Fixes: 216b44000ada ("brcmfmac: Fix use after free in brcmf_sdio_readframes()")
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Cc: Brian Norris <briannorris@xxxxxxxxxxxx>
Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Acked-by: franky.lin@xxxxxxxxxxxx
Acked-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
[bwh: Backported to 3.16:
- Use bus->sdiodev->func[1] instead of ->func1
- Adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_sdio.c
@@ -1971,6 +1971,8 @@ static uint brcmf_sdio_readframes(struct
if (brcmf_sdio_hdparse(bus, bus->rxhdr, &rd_new,
BRCMF_SDIO_FT_NORMAL)) {
rd->len = 0;
+ brcmf_sdio_rxfail(bus, true, true);
+ sdio_release_host(bus->sdiodev->func[1]);
brcmu_pkt_buf_free_skb(pkt);
continue;
}