diff options
| author | Oliver Neukum <oneukum@suse.com> | 2024-05-02 14:51:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-03 08:35:37 +0300 |
| commit | b3e40fc85735b787ce65909619fcd173107113c2 (patch) | |
| tree | 312550caf5b5b19dd79cc5c9622f0933e0dd0506 | |
| parent | 080e73c9411b9ebc4c22e8ee8a12a9f109b85819 (diff) | |
| download | linux-b3e40fc85735b787ce65909619fcd173107113c2.tar.xz | |
USB: usb_parse_endpoint: ignore reserved bits
Reading bEndpointAddress the spec tells is that:
b7 is direction, which must be ignored
b6:4 are reserved which are to be set to zero
b3:0 are the endpoint address
In order to be backwards compatible with possible future versions of USB
we have to be ready with devices using those bits. That means that we
also have to ignore them like we do with the direction bit.
In consequence the only illegal address you can encoding in four bits is
endpoint zero, for which no descriptor must exist. Hence the check for
exceeding the upper limit on endpoint addresses is removed.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20240502115259.31076-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/core/config.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 7f8d33f92ddb..3362af165ef5 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -279,11 +279,11 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, goto skip_to_next_endpoint_or_interface_descriptor; } - i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK; - if (i >= 16 || i == 0) { + i = d->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK; + if (i == 0) { dev_notice(ddev, "config %d interface %d altsetting %d has an " - "invalid endpoint with address 0x%X, skipping\n", - cfgno, inum, asnum, d->bEndpointAddress); + "invalid descriptor for endpoint zero, skipping\n", + cfgno, inum, asnum); goto skip_to_next_endpoint_or_interface_descriptor; } |