access_ok() checks must be done on every part of the userspace structure that
is accessed. If access_ok() on one part of the struct succeeded, it does not imply
it will succeed on other parts of the struct. (Does depend on the architecture
implementation of access_ok()).
This changes the __get_user() users to first check access_ok() on the data structure.
Signed-off-by: Michael Buesch <mb@xxxxxxxxx>
Cc: stable@xxxxxxxxxx
---
drivers/usb/core/devio.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- linux-2.6.orig/drivers/usb/core/devio.c
+++ linux-2.6/drivers/usb/core/devio.c
@@ -1314,21 +1314,22 @@ static int proc_reapurbnonblock(struct d
return -EAGAIN;
return processcompl(as, (void __user * __user *)arg);
}
#ifdef CONFIG_COMPAT
static int get_urb32(struct usbdevfs_urb *kurb,
struct usbdevfs_urb32 __user *uurb)
{
__u32 uptr;
- if (get_user(kurb->type, &uurb->type) ||
+ if (!access_ok(VERIFY_READ, uurb, sizeof(*uurb)) ||
+ __get_user(kurb->type, &uurb->type) ||
__get_user(kurb->endpoint, &uurb->endpoint) ||
__get_user(kurb->status, &uurb->status) ||
__get_user(kurb->flags, &uurb->flags) ||
__get_user(kurb->buffer_length, &uurb->buffer_length) ||
__get_user(kurb->actual_length, &uurb->actual_length) ||
__get_user(kurb->start_frame, &uurb->start_frame) ||
__get_user(kurb->number_of_packets, &uurb->number_of_packets) ||
__get_user(kurb->error_count, &uurb->error_count) ||
__get_user(kurb->signr, &uurb->signr))
return -EFAULT;
@@ -1529,22 +1530,23 @@ static int proc_ioctl_default(struct dev
}
#ifdef CONFIG_COMPAT
static int proc_ioctl_compat(struct dev_state *ps, compat_uptr_t arg)
{
struct usbdevfs_ioctl32 __user *uioc;
struct usbdevfs_ioctl ctrl;
u32 udata;
uioc = compat_ptr((long)arg);
- if (get_user(ctrl.ifno, &uioc->ifno) ||
- get_user(ctrl.ioctl_code, &uioc->ioctl_code) ||
+ if (!access_ok(VERIFY_READ, uioc, sizeof(*uioc)) ||
+ __get_user(ctrl.ifno, &uioc->ifno) ||
+ __get_user(ctrl.ioctl_code, &uioc->ioctl_code) ||
__get_user(udata, &uioc->data))
return -EFAULT;
ctrl.data = compat_ptr(udata);
return proc_ioctl(ps, &ctrl);
}
#endif
/*
* NOTE: All requests here that have interface numbers as parameters
--
Greetings, Michael.
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