From: Chunfeng Yun chunfeng.yun@mediatek.com
[ 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 --- 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 2ea3157ddb6e2..e65586147965d 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) @@ -484,7 +485,7 @@ 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);
@@ -523,7 +524,7 @@ 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);