From 3e4f8e21c4f27bcf30a48486b9dcc269512b79ff Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 19 Dec 2019 17:10:16 +0100 Subject: USB: core: fix check for duplicate endpoints Amend the endpoint-descriptor sanity checks to detect all duplicate endpoint addresses in a configuration. Commit 0a8fd1346254 ("USB: fix problems with duplicate endpoint addresses") added a check for duplicate endpoint addresses within a single alternate setting, but did not look for duplicate addresses in other interfaces. The current check would also not detect all duplicate addresses when one endpoint is as a (bi-directional) control endpoint. This specifically avoids overwriting the endpoint entries in struct usb_device when enabling a duplicate endpoint, something which could potentially lead to crashes or leaks, for example, when endpoints are later disabled. Cc: stable Signed-off-by: Johan Hovold Acked-by: Alan Stern Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 70 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 58 insertions(+), 12 deletions(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 5f40117e68e7..21291950cc97 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -203,9 +203,58 @@ static const unsigned short super_speed_maxpacket_maxes[4] = { [USB_ENDPOINT_XFER_INT] = 1024, }; -static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, - int asnum, struct usb_host_interface *ifp, int num_ep, - unsigned char *buffer, int size) +static bool endpoint_is_duplicate(struct usb_endpoint_descriptor *e1, + struct usb_endpoint_descriptor *e2) +{ + if (e1->bEndpointAddress == e2->bEndpointAddress) + return true; + + if (usb_endpoint_xfer_control(e1) || usb_endpoint_xfer_control(e2)) { + if (usb_endpoint_num(e1) == usb_endpoint_num(e2)) + return true; + } + + return false; +} + +/* + * Check for duplicate endpoint addresses in other interfaces and in the + * altsetting currently being parsed. + */ +static bool config_endpoint_is_duplicate(struct usb_host_config *config, + int inum, int asnum, struct usb_endpoint_descriptor *d) +{ + struct usb_endpoint_descriptor *epd; + struct usb_interface_cache *intfc; + struct usb_host_interface *alt; + int i, j, k; + + for (i = 0; i < config->desc.bNumInterfaces; ++i) { + intfc = config->intf_cache[i]; + + for (j = 0; j < intfc->num_altsetting; ++j) { + alt = &intfc->altsetting[j]; + + if (alt->desc.bInterfaceNumber == inum && + alt->desc.bAlternateSetting != asnum) + continue; + + for (k = 0; k < alt->desc.bNumEndpoints; ++k) { + epd = &alt->endpoint[k].desc; + + if (endpoint_is_duplicate(epd, d)) + return true; + } + } + } + + return false; +} + +static int usb_parse_endpoint(struct device *ddev, int cfgno, + struct usb_host_config *config, int inum, int asnum, + struct usb_host_interface *ifp, int num_ep, + unsigned char *buffer, int size) { unsigned char *buffer0 = buffer; struct usb_endpoint_descriptor *d; @@ -242,13 +291,10 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, goto skip_to_next_endpoint_or_interface_descriptor; /* Check for duplicate endpoint addresses */ - for (i = 0; i < ifp->desc.bNumEndpoints; ++i) { - if (ifp->endpoint[i].desc.bEndpointAddress == - d->bEndpointAddress) { - dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", - cfgno, inum, asnum, d->bEndpointAddress); - goto skip_to_next_endpoint_or_interface_descriptor; - } + if (config_endpoint_is_duplicate(config, inum, asnum, d)) { + dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", + cfgno, inum, asnum, d->bEndpointAddress); + goto skip_to_next_endpoint_or_interface_descriptor; } endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints]; @@ -522,8 +568,8 @@ static int usb_parse_interface(struct device *ddev, int cfgno, if (((struct usb_descriptor_header *) buffer)->bDescriptorType == USB_DT_INTERFACE) break; - retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt, - num_ep, buffer, size); + retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum, + alt, num_ep, buffer, size); if (retval < 0) return retval; ++n; -- cgit From 2548288b4fb059b2da9ceada172ef763077e8a59 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 6 Jan 2020 10:43:42 -0500 Subject: USB: Fix: Don't skip endpoint descriptors with maxpacket=0 It turns out that even though endpoints with a maxpacket length of 0 aren't useful for data transfer, the descriptors do serve other purposes. In particular, skipping them will also skip over other class-specific descriptors for classes such as UVC. This unexpected side effect has caused some UVC cameras to stop working. In addition, the USB spec requires that when isochronous endpoint descriptors are present in an interface's altsetting 0 (which is true on some devices), the maxpacket size _must_ be set to 0. Warning about such things seems like a bad idea. This patch updates an earlier commit which would log a warning and skip these endpoint descriptors. Now we only log a warning, and we don't even do that for isochronous endpoints in altsetting 0. We don't need to worry about preventing endpoints with maxpacket = 0 from ever being used for data transfers; usb_submit_urb() already checks for this. Reported-and-tested-by: Roger Whittaker Fixes: d482c7bb0541 ("USB: Skip endpoints with 0 maxpacket length") Signed-off-by: Alan Stern CC: Laurent Pinchart Link: https://marc.info/?l=linux-usb&m=157790377329882&w=2 Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2001061040270.1514-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 21291950cc97..26bc05e48d8a 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -392,12 +392,16 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, endpoint->desc.wMaxPacketSize = cpu_to_le16(8); } - /* Validate the wMaxPacketSize field */ + /* + * Validate the wMaxPacketSize field. + * Some devices have isochronous endpoints in altsetting 0; + * the USB-2 spec requires such endpoints to have wMaxPacketSize = 0 + * (see the end of section 5.6.3), so don't warn about them. + */ maxp = usb_endpoint_maxp(&endpoint->desc); - if (maxp == 0) { - dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has wMaxPacketSize 0, skipping\n", + if (maxp == 0 && !(usb_endpoint_xfer_isoc(d) && asnum == 0)) { + dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid wMaxPacketSize 0\n", cfgno, inum, asnum, d->bEndpointAddress); - goto skip_to_next_endpoint_or_interface_descriptor; } /* Find the highest legal maxpacket size for this endpoint */ -- cgit