summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAlan Stern <stern@rowland.harvard.edu>2009-06-29 11:04:54 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2009-07-12 15:16:41 -0700
commit9180135bc80ab11199d482b6111e23f74d65af4a (patch)
tree570d7079252a6a7b821e42383913ec0bfa09e4eb
parentec6d67e39f5638c792eb7490bf32586ccb9d8005 (diff)
downloadlinux-3.10-9180135bc80ab11199d482b6111e23f74d65af4a.tar.gz
linux-3.10-9180135bc80ab11199d482b6111e23f74d65af4a.tar.bz2
linux-3.10-9180135bc80ab11199d482b6111e23f74d65af4a.zip
USB: handle zero-length usbfs submissions correctly
This patch (as1262) fixes a bug in usbfs: It refuses to accept zero-length transfers, and it insists that the buffer pointer be valid even if there is no data being transferred. The patch also consolidates a bunch of repetitive access_ok() checks into a single check, which incidentally fixes the lack of such a check for Isochronous URBs. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/core/devio.c41
1 files changed, 20 insertions, 21 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 46ca2af5ef1..38b8bce782d 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -995,7 +995,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
USBDEVFS_URB_ZERO_PACKET |
USBDEVFS_URB_NO_INTERRUPT))
return -EINVAL;
- if (!uurb->buffer)
+ if (uurb->buffer_length > 0 && !uurb->buffer)
return -EINVAL;
if (!(uurb->type == USBDEVFS_URB_TYPE_CONTROL &&
(uurb->endpoint & ~USB_ENDPOINT_DIR_MASK) == 0)) {
@@ -1051,11 +1051,6 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
is_in = 0;
uurb->endpoint &= ~USB_DIR_IN;
}
- if (!access_ok(is_in ? VERIFY_WRITE : VERIFY_READ,
- uurb->buffer, uurb->buffer_length)) {
- kfree(dr);
- return -EFAULT;
- }
snoop(&ps->dev->dev, "control urb: bRequest=%02x "
"bRrequestType=%02x wValue=%04x "
"wIndex=%04x wLength=%04x\n",
@@ -1075,9 +1070,6 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
uurb->number_of_packets = 0;
if (uurb->buffer_length > MAX_USBFS_BUFFER_SIZE)
return -EINVAL;
- if (!access_ok(is_in ? VERIFY_WRITE : VERIFY_READ,
- uurb->buffer, uurb->buffer_length))
- return -EFAULT;
snoop(&ps->dev->dev, "bulk urb\n");
break;
@@ -1119,28 +1111,35 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
return -EINVAL;
if (uurb->buffer_length > MAX_USBFS_BUFFER_SIZE)
return -EINVAL;
- if (!access_ok(is_in ? VERIFY_WRITE : VERIFY_READ,
- uurb->buffer, uurb->buffer_length))
- return -EFAULT;
snoop(&ps->dev->dev, "interrupt urb\n");
break;
default:
return -EINVAL;
}
- as = alloc_async(uurb->number_of_packets);
- if (!as) {
+ if (uurb->buffer_length > 0 &&
+ !access_ok(is_in ? VERIFY_WRITE : VERIFY_READ,
+ uurb->buffer, uurb->buffer_length)) {
kfree(isopkt);
kfree(dr);
- return -ENOMEM;
+ return -EFAULT;
}
- as->urb->transfer_buffer = kmalloc(uurb->buffer_length, GFP_KERNEL);
- if (!as->urb->transfer_buffer) {
+ as = alloc_async(uurb->number_of_packets);
+ if (!as) {
kfree(isopkt);
kfree(dr);
- free_async(as);
return -ENOMEM;
}
+ if (uurb->buffer_length > 0) {
+ as->urb->transfer_buffer = kmalloc(uurb->buffer_length,
+ GFP_KERNEL);
+ if (!as->urb->transfer_buffer) {
+ kfree(isopkt);
+ kfree(dr);
+ free_async(as);
+ return -ENOMEM;
+ }
+ }
as->urb->dev = ps->dev;
as->urb->pipe = (uurb->type << 30) |
__create_pipe(ps->dev, uurb->endpoint & 0xf) |
@@ -1182,7 +1181,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
kfree(isopkt);
as->ps = ps;
as->userurb = arg;
- if (uurb->endpoint & USB_DIR_IN)
+ if (is_in && uurb->buffer_length > 0)
as->userbuffer = uurb->buffer;
else
as->userbuffer = NULL;
@@ -1192,9 +1191,9 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
as->uid = cred->uid;
as->euid = cred->euid;
security_task_getsecid(current, &as->secid);
- if (!is_in) {
+ if (!is_in && uurb->buffer_length > 0) {
if (copy_from_user(as->urb->transfer_buffer, uurb->buffer,
- as->urb->transfer_buffer_length)) {
+ uurb->buffer_length)) {
free_async(as);
return -EFAULT;
}