From aed9d65ac3278d4febd8665bd7db59ef53e825fe Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 1 Aug 2016 15:25:56 -0400 Subject: USB: validate wMaxPacketValue entries in endpoint descriptors Erroneous or malicious endpoint descriptors may have non-zero bits in reserved positions, or out-of-bounds values. This patch helps prevent these from causing problems by bounds-checking the wMaxPacketValue entries in endpoint descriptors and capping the values at the maximum allowed. This issue was first discovered and tests were conducted by Jake Lamberson , an intern working for Rosie Hall. Signed-off-by: Alan Stern Reported-by: roswest Tested-by: roswest CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 66 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 63 insertions(+), 3 deletions(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 31ccdccd7a04..051163189810 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -171,6 +171,31 @@ static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno, ep, buffer, size); } +static const unsigned short low_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 8, + [USB_ENDPOINT_XFER_ISOC] = 0, + [USB_ENDPOINT_XFER_BULK] = 0, + [USB_ENDPOINT_XFER_INT] = 8, +}; +static const unsigned short full_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 64, + [USB_ENDPOINT_XFER_ISOC] = 1023, + [USB_ENDPOINT_XFER_BULK] = 64, + [USB_ENDPOINT_XFER_INT] = 64, +}; +static const unsigned short high_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 64, + [USB_ENDPOINT_XFER_ISOC] = 1024, + [USB_ENDPOINT_XFER_BULK] = 512, + [USB_ENDPOINT_XFER_INT] = 1023, +}; +static const unsigned short super_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 512, + [USB_ENDPOINT_XFER_ISOC] = 1024, + [USB_ENDPOINT_XFER_BULK] = 1024, + [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) @@ -179,6 +204,8 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, struct usb_endpoint_descriptor *d; struct usb_host_endpoint *endpoint; int n, i, j, retval; + unsigned int maxp; + const unsigned short *maxpacket_maxes; d = (struct usb_endpoint_descriptor *) buffer; buffer += d->bLength; @@ -286,6 +313,42 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, endpoint->desc.wMaxPacketSize = cpu_to_le16(8); } + /* Validate the wMaxPacketSize field */ + maxp = usb_endpoint_maxp(&endpoint->desc); + + /* Find the highest legal maxpacket size for this endpoint */ + i = 0; /* additional transactions per microframe */ + switch (to_usb_device(ddev)->speed) { + case USB_SPEED_LOW: + maxpacket_maxes = low_speed_maxpacket_maxes; + break; + case USB_SPEED_FULL: + maxpacket_maxes = full_speed_maxpacket_maxes; + break; + case USB_SPEED_HIGH: + /* Bits 12..11 are allowed only for HS periodic endpoints */ + if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) { + i = maxp & (BIT(12) | BIT(11)); + maxp &= ~i; + } + /* fallthrough */ + default: + maxpacket_maxes = high_speed_maxpacket_maxes; + break; + case USB_SPEED_SUPER: + case USB_SPEED_SUPER_PLUS: + maxpacket_maxes = super_speed_maxpacket_maxes; + break; + } + j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)]; + + if (maxp > j) { + dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n", + cfgno, inum, asnum, d->bEndpointAddress, maxp, j); + maxp = j; + endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp); + } + /* * Some buggy high speed devices have bulk endpoints using * maxpacket sizes other than 512. High speed HCDs may not @@ -293,9 +356,6 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, */ if (to_usb_device(ddev)->speed == USB_SPEED_HIGH && usb_endpoint_xfer_bulk(d)) { - unsigned maxp; - - maxp = usb_endpoint_maxp(&endpoint->desc) & 0x07ff; if (maxp != 512) dev_warn(ddev, "config %d interface %d altsetting %d " "bulk endpoint 0x%X has invalid maxpacket %d\n", -- cgit v1.2.3 From 6c73358c83ce870c0cf32413e5cadb3b9a39c606 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 22 Aug 2016 16:58:53 -0400 Subject: USB: fix typo in wMaxPacketSize validation The maximum value allowed for wMaxPacketSize of a high-speed interrupt endpoint is 1024 bytes, not 1023. Signed-off-by: Alan Stern Fixes: aed9d65ac327 ("USB: validate wMaxPacketValue entries in endpoint descriptors") CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 051163189810..15ce4ab11688 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -187,7 +187,7 @@ static const unsigned short high_speed_maxpacket_maxes[4] = { [USB_ENDPOINT_XFER_CONTROL] = 64, [USB_ENDPOINT_XFER_ISOC] = 1024, [USB_ENDPOINT_XFER_BULK] = 512, - [USB_ENDPOINT_XFER_INT] = 1023, + [USB_ENDPOINT_XFER_INT] = 1024, }; static const unsigned short super_speed_maxpacket_maxes[4] = { [USB_ENDPOINT_XFER_CONTROL] = 512, -- cgit v1.2.3 From 08c5cd37480f59ea39682f4585d92269be6b1424 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 16 Sep 2016 10:24:26 -0400 Subject: USB: change bInterval default to 10 ms Some full-speed mceusb infrared transceivers contain invalid endpoint descriptors for their interrupt endpoints, with bInterval set to 0. In the past they have worked out okay with the mceusb driver, because the driver sets the bInterval field in the descriptor to 1, overwriting whatever value may have been there before. However, this approach was never sanctioned by the USB core, and in fact it does not work with xHCI controllers, because they use the bInterval value that was present when the configuration was installed. Currently usbcore uses 32 ms as the default interval if the value in the endpoint descriptor is invalid. It turns out that these IR transceivers don't work properly unless the interval is set to 10 ms or below. To work around this mceusb problem, this patch changes the endpoint-descriptor parsing routine, making the default interval value be 10 ms rather than 32 ms. Signed-off-by: Alan Stern Tested-by: Wade Berrier CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'drivers/usb/core/config.c') diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 15ce4ab11688..a2d90aca779f 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -240,8 +240,10 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, memcpy(&endpoint->desc, d, n); INIT_LIST_HEAD(&endpoint->urb_list); - /* Fix up bInterval values outside the legal range. Use 32 ms if no - * proper value can be guessed. */ + /* + * Fix up bInterval values outside the legal range. + * Use 10 or 8 ms if no proper value can be guessed. + */ i = 0; /* i = min, j = max, n = default */ j = 255; if (usb_endpoint_xfer_int(d)) { @@ -250,13 +252,15 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, case USB_SPEED_SUPER_PLUS: case USB_SPEED_SUPER: case USB_SPEED_HIGH: - /* Many device manufacturers are using full-speed + /* + * Many device manufacturers are using full-speed * bInterval values in high-speed interrupt endpoint - * descriptors. Try to fix those and fall back to a - * 32 ms default value otherwise. */ + * descriptors. Try to fix those and fall back to an + * 8-ms default value otherwise. + */ n = fls(d->bInterval*8); if (n == 0) - n = 9; /* 32 ms = 2^(9-1) uframes */ + n = 7; /* 8 ms = 2^(7-1) uframes */ j = 16; /* @@ -271,10 +275,12 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, } break; default: /* USB_SPEED_FULL or _LOW */ - /* For low-speed, 10 ms is the official minimum. + /* + * For low-speed, 10 ms is the official minimum. * But some "overclocked" devices might want faster - * polling so we'll allow it. */ - n = 32; + * polling so we'll allow it. + */ + n = 10; break; } } else if (usb_endpoint_xfer_isoc(d)) { @@ -282,10 +288,10 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, j = 16; switch (to_usb_device(ddev)->speed) { case USB_SPEED_HIGH: - n = 9; /* 32 ms = 2^(9-1) uframes */ + n = 7; /* 8 ms = 2^(7-1) uframes */ break; default: /* USB_SPEED_FULL */ - n = 6; /* 32 ms = 2^(6-1) frames */ + n = 4; /* 8 ms = 2^(4-1) frames */ break; } } -- cgit v1.2.3