diff options
| author | Weitao Wang <WeitaoWang-oc@zhaoxin.com> | 2025-08-19 15:58:43 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-19 16:12:13 +0200 |
| commit | 2eb03376151bb8585caa23ed2673583107bb5193 (patch) | |
| tree | 83ab088b70be1246e4efe130086bf73713716df5 /drivers/usb/host/xhci-ring.c | |
| parent | 309b6341d5570fb2b41b923de2fc9bb147106b80 (diff) | |
usb: xhci: Fix slot_id resource race conflict
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 <WeitaoWang-oc@zhaoxin.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250819125844.2042452-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index ecd757d482c5..4f8f5aab109d 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1592,7 +1592,8 @@ static void xhci_handle_cmd_enable_slot(int slot_id, struct xhci_command *comman 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; @@ -1607,6 +1608,10 @@ 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) @@ -1856,7 +1861,7 @@ static void handle_cmd_completion(struct xhci_hcd *xhci, xhci_handle_cmd_enable_slot(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) |