From bab267adc97e3e71f924bea1a4e095e944d7163d Mon Sep 17 00:00:00 2001 From: leoliu-oc Date: Tue, 4 Nov 2025 18:02:21 +0800 Subject: [PATCH 1/2] usb: xhci: Fix slot_id resource race conflict ANBZ: #28527 commit 2eb03376151bb8585caa23ed2673583107bb5193 upstream. xHC controller may immediately reuse a slot_id after it's disabled, giving it to a new enumerating device before the xhci driver freed all resources related to the disabled device. In such a scenario, device-A with slot_id equal to 1 is disconnecting while device-B is enumerating, device-B will fail to enumerate in the follow sequence. 1.[device-A] send disable slot command 2.[device-B] send enable slot command 3.[device-A] disable slot command completed and wakeup waiting thread 4.[device-B] enable slot command completed with slot_id equal to 1 and wakeup waiting thread 5.[device-B] driver checks that slot_id is still in use (by device-A) in xhci_alloc_virt_device, and fail to enumerate due to this conflict 6.[device-A] xhci->devs[slot_id] set to NULL in xhci_free_virt_device To fix driver's slot_id resources conflict, clear xhci->devs[slot_id] and xhci->dcbba->dev_context_ptrs[slot_id] pointers in the interrupt context when disable slot command completes successfully. Simultaneously, adjust function xhci_free_virt_device to accurately handle device release. [minor smatch warning and commit message fix -Mathias] Cc: stable@vger.kernel.org Fixes: 7faac1953ed1 ("xhci: avoid race between disable slot command and host runtime suspend") Signed-off-by: Weitao Wang Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250819125844.2042452-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman Reviewed-by: Tony W. Wang Tested-by: Lyle Li Signed-off-by: leoliu-oc --- drivers/usb/host/xhci-hub.c | 3 +-- drivers/usb/host/xhci-mem.c | 22 +++++++++++----------- drivers/usb/host/xhci-ring.c | 9 +++++++-- drivers/usb/host/xhci.c | 18 +++++++++++++----- drivers/usb/host/xhci.h | 3 ++- 5 files changed, 34 insertions(+), 21 deletions(-) diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 94adae8b19f0..7157842c507e 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -630,8 +630,7 @@ static int xhci_enter_test_mode(struct xhci_hcd *xhci, if (!xhci->devs[i]) continue; - retval = xhci_disable_slot(xhci, i); - xhci_free_virt_device(xhci, i); + retval = xhci_disable_and_free_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-mem.c b/drivers/usb/host/xhci-mem.c index 5c55bf3299a3..04349616327e 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -883,21 +883,20 @@ int xhci_alloc_tt_info(struct xhci_hcd *xhci, * will be manipulated by the configure endpoint, allocate device, or update * hub functions while this function is removing the TT entries from the list. */ -void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id) +void xhci_free_virt_device(struct xhci_hcd *xhci, struct xhci_virt_device *dev, + int slot_id) { - struct xhci_virt_device *dev; int i; int old_active_eps = 0; /* Slot ID 0 is reserved */ - if (slot_id == 0 || !xhci->devs[slot_id]) + if (slot_id == 0 || !dev) return; - dev = xhci->devs[slot_id]; - - xhci->dcbaa->dev_context_ptrs[slot_id] = 0; - if (!dev) - return; + /* If device ctx array still points to _this_ device, clear it */ + if (dev->out_ctx && + xhci->dcbaa->dev_context_ptrs[slot_id] == cpu_to_le64(dev->out_ctx->dma)) + xhci->dcbaa->dev_context_ptrs[slot_id] = 0; trace_xhci_free_virt_device(dev); @@ -932,8 +931,9 @@ void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id) if (dev->udev && dev->udev->slot_id) dev->udev->slot_id = 0; - kfree(xhci->devs[slot_id]); - xhci->devs[slot_id] = NULL; + if (xhci->devs[slot_id] == dev) + xhci->devs[slot_id] = NULL; + kfree(dev); } /* @@ -975,7 +975,7 @@ static void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_i out: /* we are now at a leaf device */ xhci_debugfs_remove_slot(xhci, slot_id); - xhci_free_virt_device(xhci, slot_id); + xhci_free_virt_device(xhci, vdev, slot_id); } int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id, diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 583d90744bea..173e6864e420 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1287,7 +1287,8 @@ static void xhci_handle_cmd_enable_slot(struct xhci_hcd *xhci, int slot_id, command->slot_id = 0; } -static void xhci_handle_cmd_disable_slot(struct xhci_hcd *xhci, int slot_id) +static void xhci_handle_cmd_disable_slot(struct xhci_hcd *xhci, int slot_id, + u32 cmd_comp_code) { struct xhci_virt_device *virt_dev; struct xhci_slot_ctx *slot_ctx; @@ -1302,6 +1303,10 @@ static void xhci_handle_cmd_disable_slot(struct xhci_hcd *xhci, int slot_id) if (xhci->quirks & XHCI_EP_LIMIT_QUIRK) /* Delete default control endpoint resources */ xhci_free_device_endpoint_resources(xhci, virt_dev, true); + if (cmd_comp_code == COMP_SUCCESS) { + xhci->dcbaa->dev_context_ptrs[slot_id] = 0; + xhci->devs[slot_id] = NULL; + } } static void xhci_handle_cmd_config_ep(struct xhci_hcd *xhci, int slot_id, @@ -1541,7 +1546,7 @@ static void handle_cmd_completion(struct xhci_hcd *xhci, xhci_handle_cmd_enable_slot(xhci, slot_id, cmd, cmd_comp_code); break; case TRB_DISABLE_SLOT: - xhci_handle_cmd_disable_slot(xhci, slot_id); + xhci_handle_cmd_disable_slot(xhci, slot_id, cmd_comp_code); break; case TRB_CONFIG_EP: if (!cmd->completion) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 95840036c5f4..c848cbc0edcb 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3954,7 +3954,7 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev) xhci_disable_slot(xhci, udev->slot_id); spin_lock_irqsave(&xhci->lock, flags); - xhci_free_virt_device(xhci, udev->slot_id); + xhci_free_virt_device(xhci, virt_dev, udev->slot_id); spin_unlock_irqrestore(&xhci->lock, flags); } @@ -4003,6 +4003,16 @@ int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id) return ret; } +int xhci_disable_and_free_slot(struct xhci_hcd *xhci, u32 slot_id) +{ + struct xhci_virt_device *vdev = xhci->devs[slot_id]; + int ret; + + ret = xhci_disable_slot(xhci, slot_id); + xhci_free_virt_device(xhci, vdev, slot_id); + return ret; +} + /* * Checks if we have enough host controller resources for the default control * endpoint. @@ -4108,8 +4118,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev) return 1; disable_slot: - xhci_disable_slot(xhci, udev->slot_id); - xhci_free_virt_device(xhci, udev->slot_id); + xhci_disable_and_free_slot(xhci, udev->slot_id); return 0; } @@ -4238,8 +4247,7 @@ static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev, dev_warn(&udev->dev, "Device not responding to setup %s.\n", act); mutex_unlock(&xhci->mutex); - ret = xhci_disable_slot(xhci, udev->slot_id); - xhci_free_virt_device(xhci, udev->slot_id); + ret = xhci_disable_and_free_slot(xhci, udev->slot_id); if (!ret) { if (xhci_alloc_dev(hcd, udev) == 1) xhci_setup_addressable_virt_dev(xhci, udev); diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 0b59fb9d4bac..e658c9ca32f1 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1996,7 +1996,7 @@ void xhci_dbg_trace(struct xhci_hcd *xhci, void (*trace)(struct va_format *), /* xHCI memory management */ void xhci_mem_cleanup(struct xhci_hcd *xhci); int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags); -void xhci_free_virt_device(struct xhci_hcd *xhci, int slot_id); +void xhci_free_virt_device(struct xhci_hcd *xhci, struct xhci_virt_device *dev, int slot_id); int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id, struct usb_device *udev, gfp_t flags); int xhci_setup_addressable_virt_dev(struct xhci_hcd *xhci, struct usb_device *udev); void xhci_copy_ep0_dequeue_into_input_ctx(struct xhci_hcd *xhci, @@ -2086,6 +2086,7 @@ void xhci_init_driver(struct hc_driver *drv, int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev); void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev); int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id); +int xhci_disable_and_free_slot(struct xhci_hcd *xhci, u32 slot_id); int xhci_ext_cap_init(struct xhci_hcd *xhci); int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup); -- Gitee From 42535496d34bd245d447a30424b1b3c7e43496f4 Mon Sep 17 00:00:00 2001 From: leoliu-oc Date: Tue, 4 Nov 2025 18:02:22 +0800 Subject: [PATCH 2/2] xhci: fix memory leak regression when freeing xhci vdev devices depth first commit edcbe06453ddfde21f6aa763f7cab655f26133cc upstream. Suspend-resume cycle test revealed a memory leak in 6.17-rc3 Turns out the slot_id race fix changes accidentally ends up calling xhci_free_virt_device() with an incorrect vdev parameter. The vdev variable was reused for temporary purposes right before calling xhci_free_virt_device(). Fix this by passing the correct vdev parameter. The slot_id race fix that caused this regression was targeted for stable, so this needs to be applied there as well. Fixes: 2eb03376151b ("usb: xhci: Fix slot_id resource race conflict") Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/linux-usb/20250829181354.4450-1-00107082@163.com Suggested-by: Michal Pecio Suggested-by: David Wang <00107082@163.com> Cc: stable@vger.kernel.org Tested-by: David Wang <00107082@163.com> Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250902105306.877476-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman Reviewed-by: Tony W. Wang Tested-by: Lyle Li Signed-off-by: leoliu-oc --- drivers/usb/host/xhci-mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 04349616327e..db31f42cfa2e 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -975,7 +975,7 @@ static void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_i out: /* we are now at a leaf device */ xhci_debugfs_remove_slot(xhci, slot_id); - xhci_free_virt_device(xhci, vdev, slot_id); + xhci_free_virt_device(xhci, xhci->devs[slot_id], slot_id); } int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id, -- Gitee