This is a note to let you know that I've just added the patch titled
usb: xhci: Handle error condition in xhci_stop_device()
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 b3207c65dfafae27e7c492cb9188c0dc0eeaf3fd Mon Sep 17 00:00:00 2001
From: Mayank Rana <mrana@xxxxxxxxxxxxxx>
Date: Fri, 6 Oct 2017 17:45:30 +0300
Subject: usb: xhci: Handle error condition in xhci_stop_device()
xhci_stop_device() calls xhci_queue_stop_endpoint() multiple times
without checking the return value. xhci_queue_stop_endpoint() can
return error if the HC is already halted or unable to queue commands.
This can cause a deadlock condition as xhci_stop_device() would
end up waiting indefinitely for a completion for the command that
didn't get queued. Fix this by checking the return value and bailing
out of xhci_stop_device() in case of error. This patch happens to fix
potential memory leaks of the allocated command structures as well.
Fixes: c311e391a7ef ("xhci: rework command timeout and cancellation,")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Mayank Rana <mrana@xxxxxxxxxxxxxx>
Signed-off-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-hub.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index da9158f171cb..a2336deb5e36 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -420,14 +420,25 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
GFP_NOWAIT);
if (!command) {
spin_unlock_irqrestore(&xhci->lock, flags);
- xhci_free_command(xhci, cmd);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto cmd_cleanup;
+ }
+
+ ret = xhci_queue_stop_endpoint(xhci, command, slot_id,
+ i, suspend);
+ if (ret) {
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ xhci_free_command(xhci, command);
+ goto cmd_cleanup;
}
- xhci_queue_stop_endpoint(xhci, command, slot_id, i,
- suspend);
}
}
- xhci_queue_stop_endpoint(xhci, cmd, slot_id, 0, suspend);
+ ret = xhci_queue_stop_endpoint(xhci, cmd, slot_id, 0, suspend);
+ if (ret) {
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ goto cmd_cleanup;
+ }
+
xhci_ring_cmd_db(xhci);
spin_unlock_irqrestore(&xhci->lock, flags);
@@ -439,6 +450,8 @@ static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
xhci_warn(xhci, "Timeout while waiting for stop endpoint command\n");
ret = -ETIME;
}
+
+cmd_cleanup:
xhci_free_command(xhci, cmd);
return ret;
}
--
2.14.2