[PATCH 5.19 024/155] xhci: Fix null pointer dereference in remove if xHC has only one roothub

Greg Kroah-Hartman
2022-09-06T14:02:42Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

[ Upstream commit 4a593a62a9e3a25ab4bc37f612e4edec144f7f43 ]

The remove path in xhci platform driver tries to remove and put both main
and shared hcds even if only a main hcd exists (one roothub)

This causes a null pointer dereference in reboot for those controllers.

Check that the shared_hcd exists before trying to remove it.

Fixes: e0fe986972f5 ("usb: host: xhci-plat: prepare operation w/o shared hcd")
Reported-by: Alexey Sheplyakov <asheplyakov@basealt.ru>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220825150840.132216-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci-plat.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 044855818cb11..a8641b6536eea 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -398,12 +398,17 @@ static int xhci_plat_remove(struct platform_device *dev)
pm_runtime_get_sync(&dev->dev);
xhci->xhc_state |= XHCI_STATE_REMOVING;

- usb_remove_hcd(shared_hcd);
- xhci->shared_hcd = NULL;
+ if (shared_hcd) {
+ usb_remove_hcd(shared_hcd);
+ xhci->shared_hcd = NULL;
+ }
+
usb_phy_shutdown(hcd->usb_phy);

usb_remove_hcd(hcd);
- usb_put_hcd(shared_hcd);
+
+ if (shared_hcd)
+ usb_put_hcd(shared_hcd);

clk_disable_unprepare(clk);
clk_disable_unprepare(reg_clk);
--
2.35.1