| From 0f6f849279b5704b5d49aaa9598cb28e12b451e0 Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <johan@kernel.org> |
| Date: Thu, 19 Dec 2019 17:10:16 +0100 |
| Subject: [PATCH] USB: core: fix check for duplicate endpoints |
| |
| commit 3e4f8e21c4f27bcf30a48486b9dcc269512b79ff upstream. |
| |
| 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 <stable@vger.kernel.org> |
| Signed-off-by: Johan Hovold <johan@kernel.org> |
| Acked-by: Alan Stern <stern@rowland.harvard.edu> |
| Link: https://lore.kernel.org/r/20191219161016.6695-1-johan@kernel.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c |
| index 1ac1095bfeac..5e92c6abe306 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; |
| -- |
| 2.7.4 |
| |