d/freebsd-skq
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Fix the following bugs:

Browse Source 
- In ifc_name2unit(), disallow leading zeroes in a unit.

  Exploit: ifconfig lo01 create

- In ifc_name2unit(), properly handle overflows.  Otherwise,
  either of two local panic()'s can occur, either because
  no interface with such a name could be found after it was
  successfully created, or because the code will bogusly
  assume that it's a wildcard (unit < 0 due to overflow).

  Exploit: ifconfig lo<overflowed_integer> create

- Previous revision made the following sequence trigger
  a KASSERT() failure in queue(3):

  Exploit: ifconfig lo0 destroy; ifconfig lo0 destroy

  This is because IFC_IFLIST_REMOVE() is always called
  before ifc->ifc_destroy() has been run, not accounting
  for the fact that the latter can fail and leave the
  interface operating (like is the case for "lo0").
  So we ended up calling LIST_REMOVE() twice.  We cannot
  defer IFC_IFLIST_REMOVE() until after a call to
  ifc->ifc_destroy() because the ifnet may have been
  removed and its memory has been freed, so recover from
  this by re-inserting the ifnet in the cloned interfaces
  list if ifc->ifc_destroy() indicates a failure.
This commit is contained in:
ru 2005-11-24 18:56:14 +00:00
parent 5d85d3ca54
commit fd2f0452fd
1 changed files with 20 additions and 5 deletions
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25
sys/net/if_clone.c
View File

@ -32,6 +32,7 @@
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
@ -200,17 +201,23 @@ if_clone_destroyif(struct if_clone *ifc, struct ifnet *ifp)
{
int err;
IF_CLONE_LOCK(ifc);
IFC_IFLIST_REMOVE(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
if (ifc->ifc_destroy == NULL) {
err = EOPNOTSUPP;
goto done;
}
IF_CLONE_LOCK(ifc);
IFC_IFLIST_REMOVE(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
err = (*ifc->ifc_destroy)(ifc, ifp);
if (err != 0) {
IF_CLONE_LOCK(ifc);
IFC_IFLIST_INSERT(ifc, ifp);
IF_CLONE_UNLOCK(ifc);
}
done:
return (err);
}
@ -349,16 +356,24 @@ int
ifc_name2unit(const char *name, int *unit)
{
const char *cp;
int cutoff = INT_MAX / 10;
int cutlim = INT_MAX % 10;
for (cp = name; *cp != '\0' && (*cp < '0' || *cp > '9'); cp++);
if (*cp == '\0') {
*unit = -1;
} else if (cp[0] == '0' && cp[1] != '\0') {
/* Disallow leading zeroes. */
return (EINVAL);
} else {
for (*unit = 0; *cp != '\0'; cp++) {
if (*cp < '0' || *cp > '9') {
/* Bogus unit number. */
return (EINVAL);
}
if (*unit > cutoff ||
(*unit == cutoff && *cp - '0' > cutlim))
return (EINVAL);
*unit = (*unit * 10) + (*cp - '0');
}
}
@ -447,7 +462,7 @@ ifc_simple_attach(struct if_clone *ifc)
struct ifc_simple_data *ifcs = ifc->ifc_data;
KASSERT(ifcs->ifcs_minifs - 1 <= ifc->ifc_maxunit,
("%s: %s requested more units then allowed (%d > %d)",
("%s: %s requested more units than allowed (%d > %d)",
__func__, ifc->ifc_name, ifcs->ifcs_minifs,
ifc->ifc_maxunit + 1));