Release 4.7 kernel/groups.c
/*
* Supplementary group IDs
*/
#include <linux/cred.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/user_namespace.h>
#include <asm/uaccess.h>
struct group_info *groups_alloc(int gidsetsize)
{
struct group_info *group_info;
int nblocks;
int i;
nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
/* Make sure we always allocate at least one indirect block pointer */
nblocks = nblocks ? : 1;
group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
if (!group_info)
return NULL;
group_info->ngroups = gidsetsize;
group_info->nblocks = nblocks;
atomic_set(&group_info->usage, 1);
if (gidsetsize <= NGROUPS_SMALL)
group_info->blocks[0] = group_info->small_block;
else {
for (i = 0; i < nblocks; i++) {
kgid_t *b;
b = (void *)__get_free_page(GFP_USER);
if (!b)
goto out_undo_partial_alloc;
group_info->blocks[i] = b;
}
}
return group_info;
out_undo_partial_alloc:
while (--i >= 0) {
free_page((unsigned long)group_info->blocks[i]);
}
kfree(group_info);
return NULL;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 194 | 99.49% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 1 | 0.51% | 1 | 50.00% |
| Total | 195 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL(groups_alloc);
void groups_free(struct group_info *group_info)
{
if (group_info->blocks[0] != group_info->small_block) {
int i;
for (i = 0; i < group_info->nblocks; i++)
free_page((unsigned long)group_info->blocks[i]);
}
kfree(group_info);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 62 | 100.00% | 1 | 100.00% |
| Total | 62 | 100.00% | 1 | 100.00% |
EXPORT_SYMBOL(groups_free);
/* export the group_info to a user-space array */
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 < count; i++) {
gid_t gid;
gid = from_kgid_munged(user_ns, GROUP_AT(group_info, i));
if (put_user(gid, grouplist+i))
return -EFAULT;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 60 | 69.77% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 26 | 30.23% | 1 | 50.00% |
| Total | 86 | 100.00% | 2 | 100.00% |
/* fill a group_info from a user-space array - it must be allocated already */
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 < count; i++) {
gid_t gid;
kgid_t kgid;
if (get_user(gid, grouplist+i))
return -EFAULT;
kgid = make_kgid(user_ns, gid);
if (!gid_valid(kgid))
return -EINVAL;
GROUP_AT(group_info, i) = kgid;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 59 | 56.73% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 45 | 43.27% | 1 | 50.00% |
| Total | 104 | 100.00% | 2 | 100.00% |
/* a simple Shell sort */
static void groups_sort(struct group_info *group_info)
{
int base, max, stride;
int gidsetsize = group_info->ngroups;
for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
; /* nothing */
stride /= 3;
while (stride) {
max = gidsetsize - stride;
for (base = 0; base < max; base++) {
int left = base;
int right = left + stride;
kgid_t tmp = GROUP_AT(group_info, right);
while (left >= 0 && gid_gt(GROUP_AT(group_info, left), tmp)) {
GROUP_AT(group_info, right) =
GROUP_AT(group_info, left);
right = left;
left -= stride;
}
GROUP_AT(group_info, right) = tmp;
}
stride /= 3;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 148 | 96.73% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 5 | 3.27% | 1 | 50.00% |
| Total | 153 | 100.00% | 2 | 100.00% |
/* a simple bsearch */
int groups_search(const struct group_info *group_info, kgid_t grp)
{
unsigned int left, right;
if (!group_info)
return 0;
left = 0;
right = group_info->ngroups;
while (left < right) {
unsigned int mid = (left+right)/2;
if (gid_gt(grp, GROUP_AT(group_info, mid)))
left = mid + 1;
else if (gid_lt(grp, GROUP_AT(group_info, mid)))
right = mid;
else
return 1;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 86 | 82.69% | 1 | 33.33% |
| eric w. biederman | eric w. biederman | 9 | 8.65% | 1 | 33.33% |
| jerome marchand | jerome marchand | 9 | 8.65% | 1 | 33.33% |
| Total | 104 | 100.00% | 3 | 100.00% |
/**
* set_groups - Change a group subscription in a set of credentials
* @new: The newly prepared set of credentials to alter
* @group_info: The group list to install
*/
void set_groups(struct cred *new, struct group_info *group_info)
{
put_group_info(new->group_info);
groups_sort(group_info);
get_group_info(group_info);
new->group_info = group_info;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 37 | 97.37% | 1 | 50.00% |
| wang yanqing | wang yanqing | 1 | 2.63% | 1 | 50.00% |
| Total | 38 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL(set_groups);
/**
* set_current_groups - Change current's group subscription
* @group_info: The group list to impose
*
* Validate a group subscription and, if valid, impose it upon current's task
* security record.
*/
int set_current_groups(struct group_info *group_info)
{
struct cred *new;
new = prepare_creds();
if (!new)
return -ENOMEM;
set_groups(new, group_info);
return commit_creds(new);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 42 | 100.00% | 1 | 100.00% |
| Total | 42 | 100.00% | 1 | 100.00% |
EXPORT_SYMBOL(set_current_groups);
SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
{
const struct cred *cred = current_cred();
int i;
if (gidsetsize < 0)
return -EINVAL;
/* no need to grab task_lock here; it cannot change */
i = cred->group_info->ngroups;
if (gidsetsize) {
if (i > gidsetsize) {
i = -EINVAL;
goto out;
}
if (groups_to_user(grouplist, cred->group_info)) {
i = -EFAULT;
goto out;
}
}
out:
return i;
}
bool may_setgroups(void)
{
struct user_namespace *user_ns = current_user_ns();
return ns_capable(user_ns, CAP_SETGID) &&
userns_may_setgroups(user_ns);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| eric w. biederman | eric w. biederman | 28 | 100.00% | 2 | 100.00% |
| Total | 28 | 100.00% | 2 | 100.00% |
/*
* SMP: Our groups are copy-on-write. We can set them safely
* without another task interfering.
*/
SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
{
struct group_info *group_info;
int retval;
if (!may_setgroups())
return -EPERM;
if ((unsigned)gidsetsize > NGROUPS_MAX)
return -EINVAL;
group_info = groups_alloc(gidsetsize);
if (!group_info)
return -ENOMEM;
retval = groups_from_user(group_info, grouplist);
if (retval) {
put_group_info(group_info);
return retval;
}
retval = set_current_groups(group_info);
put_group_info(group_info);
return retval;
}
/*
* Check whether we're fsgid/egid or in the supplemental group..
*/
int in_group_p(kgid_t grp)
{
const struct cred *cred = current_cred();
int retval = 1;
if (!gid_eq(grp, cred->fsgid))
retval = groups_search(cred->group_info, grp);
return retval;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 42 | 87.50% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 6 | 12.50% | 1 | 50.00% |
| Total | 48 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL(in_group_p);
int in_egroup_p(kgid_t grp)
{
const struct cred *cred = current_cred();
int retval = 1;
if (!gid_eq(grp, cred->egid))
retval = groups_search(cred->group_info, grp);
return retval;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 42 | 87.50% | 1 | 50.00% |
| eric w. biederman | eric w. biederman | 6 | 12.50% | 1 | 50.00% |
| Total | 48 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL(in_egroup_p);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| alexey dobriyan | alexey dobriyan | 1017 | 87.67% | 1 | 11.11% |
| eric w. biederman | eric w. biederman | 131 | 11.29% | 5 | 55.56% |
| jerome marchand | jerome marchand | 9 | 0.78% | 1 | 11.11% |
| wang yanqing | wang yanqing | 2 | 0.17% | 1 | 11.11% |
| paul gortmaker | paul gortmaker | 1 | 0.09% | 1 | 11.11% |
| Total | 1160 | 100.00% | 9 | 100.00% |
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