This is a note to let you know that I've just added the patch titled
xhci: Fix NULL pointer dereference in xhci_clear_tt_buffer_complete()
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From cfbb8a84c2d2ef49bccacb511002bca4f6053555 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Date: Fri, 4 Oct 2019 14:59:33 +0300
Subject: xhci: Fix NULL pointer dereference in xhci_clear_tt_buffer_complete()
udev stored in ep->hcpriv might be NULL if tt buffer is cleared
due to a halted control endpoint during device enumeration
xhci_clear_tt_buffer_complete is called by hub_tt_work() once it's
scheduled, and by then usb core might have freed and allocated a
new udev for the next enumeration attempt.
Fixes: ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.3
Reported-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1570190373-30684-9-git-send-email-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 00f3804f7aa7..517ec3206f6e 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -5238,8 +5238,16 @@ static void xhci_clear_tt_buffer_complete(struct usb_hcd *hcd,
unsigned int ep_index;
unsigned long flags;
+ /*
+ * udev might be NULL if tt buffer is cleared during a failed device
+ * enumeration due to a halted control endpoint. Usb core might
+ * have allocated a new udev for the next enumeration attempt.
+ */
+
xhci = hcd_to_xhci(hcd);
udev = (struct usb_device *)ep->hcpriv;
+ if (!udev)
+ return;
slot_id = udev->slot_id;
ep_index = xhci_get_endpoint_index(&ep->desc);
--
2.23.0
