From 31e0456de5be379b10fea0fa94a681057114a96e Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 7 May 2019 12:39:47 -0400 Subject: media: usb: siano: Fix general protection fault in smsusb The syzkaller USB fuzzer found a general-protection-fault bug in the smsusb part of the Siano DVB driver. The fault occurs during probe because the driver assumes without checking that the device has both IN and OUT endpoints and the IN endpoint is ep1. By slightly rearranging the driver's initialization code, we can make the appropriate checks early on and thus avoid the problem. If the expected endpoints aren't present, the new code safely returns -ENODEV from the probe routine. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+53f029db71c19a47325a@syzkaller.appspotmail.com CC: Reviewed-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/siano/smsusb.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) (limited to 'drivers/media/usb') diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index 4fc03ec8a4f1..27ad14a3f831 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -400,6 +400,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) struct smsusb_device_t *dev; void *mdev; int i, rc; + int in_maxp; /* create device object */ dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL); @@ -411,6 +412,24 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) dev->udev = interface_to_usbdev(intf); dev->state = SMSUSB_DISCONNECTED; + for (i = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) { + struct usb_endpoint_descriptor *desc = + &intf->cur_altsetting->endpoint[i].desc; + + if (desc->bEndpointAddress & USB_DIR_IN) { + dev->in_ep = desc->bEndpointAddress; + in_maxp = usb_endpoint_maxp(desc); + } else { + dev->out_ep = desc->bEndpointAddress; + } + } + + pr_debug("in_ep = %02x, out_ep = %02x\n", dev->in_ep, dev->out_ep); + if (!dev->in_ep || !dev->out_ep) { /* Missing endpoints? */ + smsusb_term_device(intf); + return -ENODEV; + } + params.device_type = sms_get_board(board_id)->type; switch (params.device_type) { @@ -425,24 +444,12 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) /* fall-thru */ default: dev->buffer_size = USB2_BUFFER_SIZE; - dev->response_alignment = - le16_to_cpu(dev->udev->ep_in[1]->desc.wMaxPacketSize) - - sizeof(struct sms_msg_hdr); + dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); params.flags |= SMS_DEVICE_FAMILY2; break; } - for (i = 0; i < intf->cur_altsetting->desc.bNumEndpoints; i++) { - if (intf->cur_altsetting->endpoint[i].desc. bEndpointAddress & USB_DIR_IN) - dev->in_ep = intf->cur_altsetting->endpoint[i].desc.bEndpointAddress; - else - dev->out_ep = intf->cur_altsetting->endpoint[i].desc.bEndpointAddress; - } - - pr_debug("in_ep = %02x, out_ep = %02x\n", - dev->in_ep, dev->out_ep); - params.device = &dev->udev->dev; params.usb_device = dev->udev; params.buffer_size = dev->buffer_size; -- cgit v1.2.3 From 45457c01171fd1488a7000d1751c06ed8560ee38 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 21 May 2019 11:38:07 -0400 Subject: media: usb: siano: Fix false-positive "uninitialized variable" warning GCC complains about an apparently uninitialized variable recently added to smsusb_init_device(). It's a false positive, but to silence the warning this patch adds a trivial initialization. Signed-off-by: Alan Stern Reported-by: kbuild test robot CC: Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/siano/smsusb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/media/usb') diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index 27ad14a3f831..59b3c124b49d 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -400,7 +400,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) struct smsusb_device_t *dev; void *mdev; int i, rc; - int in_maxp; + int in_maxp = 0; /* create device object */ dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL); -- cgit v1.2.3 From a47686636d84eaec5c9c6e84bd5f96bed34d526d Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 24 May 2019 10:59:43 -0400 Subject: media: smsusb: better handle optional alignment Most Siano devices require an alignment for the response. Changeset f3be52b0056a ("media: usb: siano: Fix general protection fault in smsusb") changed the logic with gets such aligment, but it now produces a sparce warning: drivers/media/usb/siano/smsusb.c: In function 'smsusb_init_device': drivers/media/usb/siano/smsusb.c:447:37: warning: 'in_maxp' may be used uninitialized in this function [-Wmaybe-uninitialized] 447 | dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~ The sparse message itself is bogus, but a broken (or fake) USB eeprom could produce a negative value for response_alignment. So, change the code in order to check if the result is not negative. Fixes: 31e0456de5be ("media: usb: siano: Fix general protection fault in smsusb") CC: Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/siano/smsusb.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/media/usb') diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index 59b3c124b49d..e39f3f40dfdd 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -400,7 +400,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) struct smsusb_device_t *dev; void *mdev; int i, rc; - int in_maxp = 0; + int align = 0; /* create device object */ dev = kzalloc(sizeof(struct smsusb_device_t), GFP_KERNEL); @@ -418,14 +418,14 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) if (desc->bEndpointAddress & USB_DIR_IN) { dev->in_ep = desc->bEndpointAddress; - in_maxp = usb_endpoint_maxp(desc); + align = usb_endpoint_maxp(desc) - sizeof(struct sms_msg_hdr); } else { dev->out_ep = desc->bEndpointAddress; } } pr_debug("in_ep = %02x, out_ep = %02x\n", dev->in_ep, dev->out_ep); - if (!dev->in_ep || !dev->out_ep) { /* Missing endpoints? */ + if (!dev->in_ep || !dev->out_ep || align < 0) { /* Missing endpoints? */ smsusb_term_device(intf); return -ENODEV; } @@ -444,7 +444,7 @@ static int smsusb_init_device(struct usb_interface *intf, int board_id) /* fall-thru */ default: dev->buffer_size = USB2_BUFFER_SIZE; - dev->response_alignment = in_maxp - sizeof(struct sms_msg_hdr); + dev->response_alignment = align; params.flags |= SMS_DEVICE_FAMILY2; break; -- cgit v1.2.3