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groups: move code to kernel/groups.c
Move supplementary groups implementation to kernel/groups.c . kernel/sys.c already accumulated quite a few random stuff. Do strictly copy/paste + add required headers to compile. Compile-tested on many configs and archs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan
Linus Torvalds
parent
8b0b1db013
commit
30639b6af8
@ -11,6 +11,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o \
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hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
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notifier.o ksysfs.o pm_qos_params.o sched_clock.o cred.o \
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async.o
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obj-y += groups.o
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ifdef CONFIG_FUNCTION_TRACER
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# Do not trace debug files and internal ftrace files
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288
kernel/groups.c
Normal file
288
kernel/groups.c
Normal file
@ -0,0 +1,288 @@
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/*
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* Supplementary group IDs
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*/
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#include <linux/cred.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/security.h>
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#include <linux/syscalls.h>
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#include <asm/uaccess.h>
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/* init to 2 - one for init_task, one to ensure it is never freed */
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struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
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struct group_info *groups_alloc(int gidsetsize)
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{
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struct group_info *group_info;
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int nblocks;
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int i;
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nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
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/* Make sure we always allocate at least one indirect block pointer */
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nblocks = nblocks ? : 1;
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group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
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if (!group_info)
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return NULL;
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group_info->ngroups = gidsetsize;
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group_info->nblocks = nblocks;
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atomic_set(&group_info->usage, 1);
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if (gidsetsize <= NGROUPS_SMALL)
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group_info->blocks[0] = group_info->small_block;
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else {
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for (i = 0; i < nblocks; i++) {
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gid_t *b;
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b = (void *)__get_free_page(GFP_USER);
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if (!b)
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goto out_undo_partial_alloc;
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group_info->blocks[i] = b;
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}
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}
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return group_info;
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out_undo_partial_alloc:
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while (--i >= 0) {
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free_page((unsigned long)group_info->blocks[i]);
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}
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kfree(group_info);
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return NULL;
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}
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EXPORT_SYMBOL(groups_alloc);
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void groups_free(struct group_info *group_info)
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{
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if (group_info->blocks[0] != group_info->small_block) {
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int i;
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for (i = 0; i < group_info->nblocks; i++)
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free_page((unsigned long)group_info->blocks[i]);
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}
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kfree(group_info);
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}
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EXPORT_SYMBOL(groups_free);
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/* export the group_info to a user-space array */
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static int groups_to_user(gid_t __user *grouplist,
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const struct group_info *group_info)
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{
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int i;
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unsigned int count = group_info->ngroups;
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for (i = 0; i < group_info->nblocks; i++) {
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unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
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unsigned int len = cp_count * sizeof(*grouplist);
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if (copy_to_user(grouplist, group_info->blocks[i], len))
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return -EFAULT;
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grouplist += NGROUPS_PER_BLOCK;
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count -= cp_count;
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}
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return 0;
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}
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/* fill a group_info from a user-space array - it must be allocated already */
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static int groups_from_user(struct group_info *group_info,
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gid_t __user *grouplist)
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{
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int i;
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unsigned int count = group_info->ngroups;
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for (i = 0; i < group_info->nblocks; i++) {
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unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
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unsigned int len = cp_count * sizeof(*grouplist);
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if (copy_from_user(group_info->blocks[i], grouplist, len))
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return -EFAULT;
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grouplist += NGROUPS_PER_BLOCK;
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count -= cp_count;
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}
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return 0;
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}
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/* a simple Shell sort */
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static void groups_sort(struct group_info *group_info)
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{
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int base, max, stride;
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int gidsetsize = group_info->ngroups;
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for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
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; /* nothing */
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stride /= 3;
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while (stride) {
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max = gidsetsize - stride;
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for (base = 0; base < max; base++) {
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int left = base;
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int right = left + stride;
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gid_t tmp = GROUP_AT(group_info, right);
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while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
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GROUP_AT(group_info, right) =
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GROUP_AT(group_info, left);
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right = left;
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left -= stride;
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}
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GROUP_AT(group_info, right) = tmp;
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}
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stride /= 3;
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}
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}
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/* a simple bsearch */
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int groups_search(const struct group_info *group_info, gid_t grp)
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{
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unsigned int left, right;
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if (!group_info)
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return 0;
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left = 0;
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right = group_info->ngroups;
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while (left < right) {
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unsigned int mid = (left+right)/2;
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int cmp = grp - GROUP_AT(group_info, mid);
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if (cmp > 0)
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left = mid + 1;
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else if (cmp < 0)
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right = mid;
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else
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return 1;
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}
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return 0;
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}
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/**
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* set_groups - Change a group subscription in a set of credentials
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* @new: The newly prepared set of credentials to alter
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* @group_info: The group list to install
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*
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* Validate a group subscription and, if valid, insert it into a set
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* of credentials.
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*/
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int set_groups(struct cred *new, struct group_info *group_info)
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{
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int retval;
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retval = security_task_setgroups(group_info);
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if (retval)
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return retval;
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put_group_info(new->group_info);
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groups_sort(group_info);
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get_group_info(group_info);
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new->group_info = group_info;
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return 0;
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}
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EXPORT_SYMBOL(set_groups);
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/**
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* set_current_groups - Change current's group subscription
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* @group_info: The group list to impose
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*
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* Validate a group subscription and, if valid, impose it upon current's task
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* security record.
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*/
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int set_current_groups(struct group_info *group_info)
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{
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struct cred *new;
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int ret;
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new = prepare_creds();
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if (!new)
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return -ENOMEM;
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ret = set_groups(new, group_info);
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if (ret < 0) {
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abort_creds(new);
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return ret;
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}
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return commit_creds(new);
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}
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EXPORT_SYMBOL(set_current_groups);
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SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
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{
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const struct cred *cred = current_cred();
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int i;
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if (gidsetsize < 0)
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return -EINVAL;
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/* no need to grab task_lock here; it cannot change */
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i = cred->group_info->ngroups;
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if (gidsetsize) {
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if (i > gidsetsize) {
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i = -EINVAL;
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goto out;
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}
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if (groups_to_user(grouplist, cred->group_info)) {
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i = -EFAULT;
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goto out;
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}
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}
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out:
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return i;
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}
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/*
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* SMP: Our groups are copy-on-write. We can set them safely
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* without another task interfering.
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*/
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SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
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{
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struct group_info *group_info;
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int retval;
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if (!capable(CAP_SETGID))
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return -EPERM;
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if ((unsigned)gidsetsize > NGROUPS_MAX)
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return -EINVAL;
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group_info = groups_alloc(gidsetsize);
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if (!group_info)
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return -ENOMEM;
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retval = groups_from_user(group_info, grouplist);
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if (retval) {
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put_group_info(group_info);
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return retval;
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}
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retval = set_current_groups(group_info);
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put_group_info(group_info);
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return retval;
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}
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/*
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* Check whether we're fsgid/egid or in the supplemental group..
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*/
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int in_group_p(gid_t grp)
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{
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const struct cred *cred = current_cred();
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int retval = 1;
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if (grp != cred->fsgid)
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retval = groups_search(cred->group_info, grp);
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return retval;
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}
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EXPORT_SYMBOL(in_group_p);
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int in_egroup_p(gid_t grp)
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{
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const struct cred *cred = current_cred();
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int retval = 1;
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if (grp != cred->egid)
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retval = groups_search(cred->group_info, grp);
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return retval;
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}
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EXPORT_SYMBOL(in_egroup_p);
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283
kernel/sys.c
283
kernel/sys.c
@ -1113,289 +1113,6 @@ out:
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return err;
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}
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/*
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* Supplementary group IDs
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*/
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/* init to 2 - one for init_task, one to ensure it is never freed */
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struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
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struct group_info *groups_alloc(int gidsetsize)
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{
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struct group_info *group_info;
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int nblocks;
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int i;
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nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
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/* Make sure we always allocate at least one indirect block pointer */
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nblocks = nblocks ? : 1;
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group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
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if (!group_info)
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return NULL;
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group_info->ngroups = gidsetsize;
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group_info->nblocks = nblocks;
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atomic_set(&group_info->usage, 1);
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if (gidsetsize <= NGROUPS_SMALL)
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group_info->blocks[0] = group_info->small_block;
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else {
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for (i = 0; i < nblocks; i++) {
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gid_t *b;
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b = (void *)__get_free_page(GFP_USER);
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if (!b)
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goto out_undo_partial_alloc;
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group_info->blocks[i] = b;
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}
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}
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return group_info;
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out_undo_partial_alloc:
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while (--i >= 0) {
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free_page((unsigned long)group_info->blocks[i]);
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}
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kfree(group_info);
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return NULL;
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}
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EXPORT_SYMBOL(groups_alloc);
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void groups_free(struct group_info *group_info)
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{
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if (group_info->blocks[0] != group_info->small_block) {
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int i;
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for (i = 0; i < group_info->nblocks; i++)
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free_page((unsigned long)group_info->blocks[i]);
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}
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kfree(group_info);
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}
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EXPORT_SYMBOL(groups_free);
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/* export the group_info to a user-space array */
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static int groups_to_user(gid_t __user *grouplist,
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const struct group_info *group_info)
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{
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int i;
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unsigned int count = group_info->ngroups;
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for (i = 0; i < group_info->nblocks; i++) {
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unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
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unsigned int len = cp_count * sizeof(*grouplist);
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if (copy_to_user(grouplist, group_info->blocks[i], len))
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return -EFAULT;
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grouplist += NGROUPS_PER_BLOCK;
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count -= cp_count;
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}
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return 0;
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}
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/* fill a group_info from a user-space array - it must be allocated already */
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static int groups_from_user(struct group_info *group_info,
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gid_t __user *grouplist)
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{
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int i;
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unsigned int count = group_info->ngroups;
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for (i = 0; i < group_info->nblocks; i++) {
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unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
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unsigned int len = cp_count * sizeof(*grouplist);
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if (copy_from_user(group_info->blocks[i], grouplist, len))
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return -EFAULT;
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grouplist += NGROUPS_PER_BLOCK;
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count -= cp_count;
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}
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return 0;
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}
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/* a simple Shell sort */
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static void groups_sort(struct group_info *group_info)
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{
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int base, max, stride;
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int gidsetsize = group_info->ngroups;
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for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
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; /* nothing */
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stride /= 3;
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while (stride) {
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max = gidsetsize - stride;
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for (base = 0; base < max; base++) {
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int left = base;
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int right = left + stride;
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gid_t tmp = GROUP_AT(group_info, right);
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while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
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GROUP_AT(group_info, right) =
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GROUP_AT(group_info, left);
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right = left;
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left -= stride;
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}
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GROUP_AT(group_info, right) = tmp;
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}
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stride /= 3;
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}
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}
|
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|
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/* a simple bsearch */
|
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int groups_search(const struct group_info *group_info, gid_t grp)
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{
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unsigned int left, right;
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|
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if (!group_info)
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return 0;
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|
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left = 0;
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right = group_info->ngroups;
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while (left < right) {
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unsigned int mid = (left+right)/2;
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int cmp = grp - GROUP_AT(group_info, mid);
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if (cmp > 0)
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left = mid + 1;
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else if (cmp < 0)
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right = mid;
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else
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return 1;
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}
|
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return 0;
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}
|
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|
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/**
|
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* set_groups - Change a group subscription in a set of credentials
|
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* @new: The newly prepared set of credentials to alter
|
||||
* @group_info: The group list to install
|
||||
*
|
||||
* Validate a group subscription and, if valid, insert it into a set
|
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* of credentials.
|
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*/
|
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int set_groups(struct cred *new, struct group_info *group_info)
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{
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int retval;
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retval = security_task_setgroups(group_info);
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if (retval)
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return retval;
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|
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put_group_info(new->group_info);
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groups_sort(group_info);
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get_group_info(group_info);
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new->group_info = group_info;
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return 0;
|
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}
|
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|
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EXPORT_SYMBOL(set_groups);
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|
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/**
|
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* 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)
|
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{
|
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struct cred *new;
|
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int ret;
|
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|
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new = prepare_creds();
|
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if (!new)
|
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return -ENOMEM;
|
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|
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ret = set_groups(new, group_info);
|
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if (ret < 0) {
|
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abort_creds(new);
|
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return ret;
|
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}
|
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|
||||
return commit_creds(new);
|
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}
|
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|
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EXPORT_SYMBOL(set_current_groups);
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|
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SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
|
||||
{
|
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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;
|
||||
}
|
||||
|
||||
/*
|
||||
* 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 (!capable(CAP_SETGID))
|
||||
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(gid_t grp)
|
||||
{
|
||||
const struct cred *cred = current_cred();
|
||||
int retval = 1;
|
||||
|
||||
if (grp != cred->fsgid)
|
||||
retval = groups_search(cred->group_info, grp);
|
||||
return retval;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(in_group_p);
|
||||
|
||||
int in_egroup_p(gid_t grp)
|
||||
{
|
||||
const struct cred *cred = current_cred();
|
||||
int retval = 1;
|
||||
|
||||
if (grp != cred->egid)
|
||||
retval = groups_search(cred->group_info, grp);
|
||||
return retval;
|
||||
}
|
||||
|
||||
EXPORT_SYMBOL(in_egroup_p);
|
||||
|
||||
DECLARE_RWSEM(uts_sem);
|
||||
|
||||
SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user