userns: Convert group_info values from gid_t to kgid_t.
As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values. Unless user namespaces are used this change should
have no effect.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/kernel/groups.c b/kernel/groups.c
index 99b53d1..84156f2 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -31,7 +31,7 @@
group_info->blocks[0] = group_info->small_block;
else {
for (i = 0; i < nblocks; i++) {
- gid_t *b;
+ kgid_t *b;
b = (void *)__get_free_page(GFP_USER);
if (!b)
goto out_undo_partial_alloc;
@@ -66,18 +66,15 @@
static int groups_to_user(gid_t __user *grouplist,
const struct group_info *group_info)
{
+ struct user_namespace *user_ns = current_user_ns();
int i;
unsigned int count = group_info->ngroups;
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_to_user(grouplist, group_info->blocks[i], len))
+ for (i = 0; i < count; i++) {
+ gid_t gid;
+ gid = from_kgid_munged(user_ns, GROUP_AT(group_info, i));
+ if (put_user(gid, grouplist+i))
return -EFAULT;
-
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
}
return 0;
}
@@ -86,18 +83,21 @@
static int groups_from_user(struct group_info *group_info,
gid_t __user *grouplist)
{
+ struct user_namespace *user_ns = current_user_ns();
int i;
unsigned int count = group_info->ngroups;
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_from_user(group_info->blocks[i], grouplist, len))
+ for (i = 0; i < count; i++) {
+ gid_t gid;
+ kgid_t kgid;
+ if (get_user(gid, grouplist+i))
return -EFAULT;
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
+ kgid = make_kgid(user_ns, gid);
+ if (!gid_valid(kgid))
+ return -EINVAL;
+
+ GROUP_AT(group_info, i) = kgid;
}
return 0;
}
@@ -117,9 +117,9 @@
for (base = 0; base < max; base++) {
int left = base;
int right = left + stride;
- gid_t tmp = GROUP_AT(group_info, right);
+ kgid_t tmp = GROUP_AT(group_info, right);
- while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
+ while (left >= 0 && gid_gt(GROUP_AT(group_info, left), tmp)) {
GROUP_AT(group_info, right) =
GROUP_AT(group_info, left);
right = left;
@@ -132,7 +132,7 @@
}
/* a simple bsearch */
-int groups_search(const struct group_info *group_info, gid_t grp)
+int groups_search(const struct group_info *group_info, kgid_t grp)
{
unsigned int left, right;
@@ -143,9 +143,9 @@
right = group_info->ngroups;
while (left < right) {
unsigned int mid = (left+right)/2;
- if (grp > GROUP_AT(group_info, mid))
+ if (gid_gt(grp, GROUP_AT(group_info, mid)))
left = mid + 1;
- else if (grp < GROUP_AT(group_info, mid))
+ else if (gid_lt(grp, GROUP_AT(group_info, mid)))
right = mid;
else
return 1;
@@ -262,7 +262,8 @@
int retval = 1;
if (grp != cred->fsgid)
- retval = groups_search(cred->group_info, grp);
+ retval = groups_search(cred->group_info,
+ make_kgid(cred->user_ns, grp));
return retval;
}
@@ -274,7 +275,8 @@
int retval = 1;
if (grp != cred->egid)
- retval = groups_search(cred->group_info, grp);
+ retval = groups_search(cred->group_info,
+ make_kgid(cred->user_ns, grp));
return retval;
}