From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: Mon, 17 Apr 2023 10:51:59 +0800
Subject: [PATCH] usb: mtu3: fix kernel panic at qmu transfer done irq handler
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: d28f4091ea7ec3510fd6a3c6d433234e7a2bef14
[ Upstream commit d28f4091ea7ec3510fd6a3c6d433234e7a2bef14 ]
When handle qmu transfer irq, it will unlock @mtu->lock before give back
request, if another thread handle disconnect event at the same time, and
try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu
irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before
handling it.
e.g.
qmu done irq on cpu0 thread running on cpu1
qmu_done_tx()
handle gpd [0]
mtu3_requ_complete() mtu3_gadget_ep_disable()
unlock @mtu->lock
give back request lock @mtu->lock
mtu3_ep_disable()
mtu3_gpd_ring_free()
unlock @mtu->lock
lock @mtu->lock
get next gpd [1]
[1]: goto [0] to handle next gpd, and next gpd may be NULL.
Fixes: 48e0d3735aa5 ("usb: mtu3: supports new QMU format")
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20230417025203.18097-3-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/usb/mtu3/mtu3_qmu.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c
index a2fdab8b..3b68a0a1 100644
--- a/drivers/usb/mtu3/mtu3_qmu.c
+++ b/drivers/usb/mtu3/mtu3_qmu.c
@@ -210,6 +210,7 @@ static struct qmu_gpd *advance_enq_gpd(struct mtu3_gpd_ring *ring)
return ring->enqueue;
}
+/* @dequeue may be NULL if ring is unallocated or freed */
static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring)
{
if (ring->dequeue < ring->end)
@@ -491,7 +492,7 @@ static void qmu_done_tx(struct mtu3 *mtu, u8 epnum)
dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
__func__, epnum, gpd, gpd_current, ring->enqueue);
- while (gpd != gpd_current && !GET_GPD_HWO(gpd)) {
+ while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) {
mreq = next_request(mep);
@@ -530,7 +531,7 @@ static void qmu_done_rx(struct mtu3 *mtu, u8 epnum)
dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n",
__func__, epnum, gpd, gpd_current, ring->enqueue);
- while (gpd != gpd_current && !GET_GPD_HWO(gpd)) {
+ while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) {
mreq = next_request(mep);
--
2.35.3