From b3207c65dfafae27e7c492cb9188c0dc0eeaf3fd Mon Sep 17 00:00:00 2001 From: Mayank Rana Date: Fri, 6 Oct 2017 17:45:30 +0300 Subject: [PATCH] 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: Signed-off-by: Mayank Rana Signed-off-by: Jack Pham Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- 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 da9158f..a2336de 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; } -- 2.7.4