[PATCH 4.9 071/175] usb: gadget: mv_u3d: request_irq() after initializing UDC

From: Greg Kroah-Hartman
Date: Mon Sep 20 2021 - 13:04:42 EST


From: Nadezda Lutovinova <lutovinova@xxxxxxxxx>

[ Upstream commit 2af0c5ffadaf9d13eca28409d4238b4e672942d3 ]

If IRQ occurs between calling request_irq() and mv_u3d_eps_init(),
then null pointer dereference occurs since u3d->eps[] wasn't
initialized yet but used in mv_u3d_nuke().

The patch puts registration of the interrupt handler after
initializing of neccesery data.

Found by Linux Driver Verification project (linuxtesting.org).

Fixes: 90fccb529d24 ("usb: gadget: Gadget directory cleanup - group UDC drivers")
Acked-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Nadezda Lutovinova <lutovinova@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210818141247.4794-1-lutovinova@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/gadget/udc/mv_u3d_core.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/gadget/udc/mv_u3d_core.c b/drivers/usb/gadget/udc/mv_u3d_core.c
index b9e19a591322..d75c6449616b 100644
--- a/drivers/usb/gadget/udc/mv_u3d_core.c
+++ b/drivers/usb/gadget/udc/mv_u3d_core.c
@@ -1912,14 +1912,6 @@ static int mv_u3d_probe(struct platform_device *dev)
goto err_get_irq;
}
u3d->irq = r->start;
- if (request_irq(u3d->irq, mv_u3d_irq,
- IRQF_SHARED, driver_name, u3d)) {
- u3d->irq = 0;
- dev_err(&dev->dev, "Request irq %d for u3d failed\n",
- u3d->irq);
- retval = -ENODEV;
- goto err_request_irq;
- }

/* initialize gadget structure */
u3d->gadget.ops = &mv_u3d_ops; /* usb_gadget_ops */
@@ -1932,6 +1924,15 @@ static int mv_u3d_probe(struct platform_device *dev)

mv_u3d_eps_init(u3d);

+ if (request_irq(u3d->irq, mv_u3d_irq,
+ IRQF_SHARED, driver_name, u3d)) {
+ u3d->irq = 0;
+ dev_err(&dev->dev, "Request irq %d for u3d failed\n",
+ u3d->irq);
+ retval = -ENODEV;
+ goto err_request_irq;
+ }
+
/* external vbus detection */
if (u3d->vbus) {
u3d->clock_gating = 1;
@@ -1955,8 +1956,8 @@ static int mv_u3d_probe(struct platform_device *dev)

err_unregister:
free_irq(u3d->irq, u3d);
-err_request_irq:
err_get_irq:
+err_request_irq:
kfree(u3d->status_req);
err_alloc_status_req:
kfree(u3d->eps);
--
2.30.2