On 27.07.2017 05:21, Lu Baolu wrote:
xhci_disable_slot() allows the invoker to pass a command pointer
as paramenter. Otherwise, it will allocate one. This will cause
memory leak when a command structure was allocated inside of this
function while queuing command trb fails. Another problem comes up
when the invoker passed a command pointer, but xhci_disable_slot()
frees it when it detects a dead host.
This patch fixes these two problems by removing the command parameter
from xhci_disable_slot().
Fixes: f9e609b82479 ("usb: xhci: Add helper function xhci_disable_slot().")
Cc: Guoqing Zhang <guoqing.zhang@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/usb/host/xhci-hub.c | 2 +-
drivers/usb/host/xhci.c | 30 +++++++++---------------------
drivers/usb/host/xhci.h | 3 +--
3 files changed, 11 insertions(+), 24 deletions(-)
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 00721e8..c862d53 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -612,7 +612,7 @@ static int xhci_enter_test_mode(struct xhci_hcd *xhci,
xhci_dbg(xhci, "Disable all slots\n");
spin_unlock_irqrestore(&xhci->lock, *flags);
for (i = 1; i <= HCS_MAX_SLOTS(xhci->hcs_params1); i++) {
- retval = xhci_disable_slot(xhci, NULL, i);
+ retval = xhci_disable_slot(xhci, i);
if (retval)
xhci_err(xhci, "Failed to disable slot %d, %d. Enter test mode anyway\n",
i, retval);
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e69073f..cb2461a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3519,11 +3519,6 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
struct xhci_virt_device *virt_dev;
struct xhci_slot_ctx *slot_ctx;
int i, ret;
- struct xhci_command *command;
-
- command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
- if (!command)
- return;
#ifndef CONFIG_USB_DEFAULT_PERSIST
/*
@@ -3539,10 +3534,8 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
/* If the host is halted due to driver unload, we still need to free the
* device.
*/
- if (ret <= 0 && ret != -ENODEV) {
- kfree(command);
+ if (ret <= 0 && ret != -ENODEV)
return;
- }
virt_dev = xhci->devs[udev->slot_id];
slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
@@ -3554,22 +3547,21 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
del_timer_sync(&virt_dev->eps[i].stop_cmd_timer);
}
- xhci_disable_slot(xhci, command, udev->slot_id);
+ xhci_disable_slot(xhci, udev->slot_id);
/*
* Event command completion handler will free any data structures
* associated with the slot. XXX Can free sleep?
*/
}
-int xhci_disable_slot(struct xhci_hcd *xhci, struct xhci_command *command,
- u32 slot_id)
+int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id)
{
+ struct xhci_command *command;
unsigned long flags;
u32 state;
int ret = 0;
- if (!command)
- command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
+ command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
if (!command)
return -ENOMEM;
@@ -3588,7 +3580,7 @@ int xhci_disable_slot(struct xhci_hcd *xhci, struct xhci_command *command,
slot_id);
if (ret) {
spin_unlock_irqrestore(&xhci->lock, flags);
- xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
+ kfree(command);
return ret;
}
xhci_ring_cmd_db(xhci);
@@ -3663,6 +3655,8 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
return 0;
}
+ xhci_free_command(xhci, command);
+
if ((xhci->quirks & XHCI_EP_LIMIT_QUIRK)) {
spin_lock_irqsave(&xhci->lock, flags);
ret = xhci_reserve_host_control_ep_resources(xhci);
@@ -3698,18 +3692,12 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
pm_runtime_get_noresume(hcd->self.controller);
#endif
-
- xhci_free_command(xhci, command);
/* Is this a LS or FS device under a HS hub? */
/* Hub or peripherial? */
return 1;
disable_slot:
- /* Disable slot, if we can do it without mem alloc */
- kfree(command->completion);
- command->completion = NULL;
- command->status = 0;
- return xhci_disable_slot(xhci, command, udev->slot_id);
+ return xhci_disable_slot(xhci, udev->slot_id);
avoiding allocating a new command after failing to allocate a virt dev was
probably the reason why xhci_disable_slot() supported a command
as a parameter in the first place.
But this is such a small corner case, and your patch fixes two more likely issues,
and simplifies the code a lot so I think It's well worth it
-Mathias
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