This is a note to let you know that I've just added the patch titled usb: xhci: Fix potential memory leak in xhci_disable_slot() to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-xhci-fix-potential-memory-leak-in-xhci_disable_slot.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From cd3f1790b006d91786728c20a01da21ee277aff1 Mon Sep 17 00:00:00 2001 From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Date: Thu, 5 Oct 2017 11:21:41 +0300 Subject: usb: xhci: Fix potential memory leak in xhci_disable_slot() From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> commit cd3f1790b006d91786728c20a01da21ee277aff1 upstream. 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> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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(-) --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -637,7 +637,7 @@ static int xhci_enter_test_mode(struct x if (!xhci->devs[i]) continue; - 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); --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3523,11 +3523,6 @@ static void xhci_free_dev(struct usb_hcd 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 /* @@ -3543,10 +3538,8 @@ static void xhci_free_dev(struct usb_hcd /* 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); @@ -3558,22 +3551,21 @@ static void xhci_free_dev(struct usb_hcd 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; @@ -3591,7 +3583,7 @@ int xhci_disable_slot(struct xhci_hcd *x 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); @@ -3666,6 +3658,8 @@ int xhci_alloc_dev(struct usb_hcd *hcd, 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); @@ -3701,18 +3695,12 @@ int xhci_alloc_dev(struct usb_hcd *hcd, 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); } /* --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -2014,8 +2014,7 @@ int xhci_run(struct usb_hcd *hcd); int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks); void xhci_init_driver(struct hc_driver *drv, const struct xhci_driver_overrides *over); -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); int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup); int xhci_resume(struct xhci_hcd *xhci, bool hibernated); Patches currently in stable-queue which might be from baolu.lu@xxxxxxxxxxxxxxx are queue-4.14/usb-xhci-disable-slot-even-when-virt-dev-is-null.patch queue-4.14/usb-xhci-fix-potential-memory-leak-in-xhci_disable_slot.patch