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CRED: Wrap task credential accesses in the capabilities code

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Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Andrew G. Morgan <morgan@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
David Howells 2008-11-14 10:39:11 +11:00 committed by James Morris
parent 47d804bfa1
commit b103c59883
1 changed files with 18 additions and 12 deletions
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30
security/commoncap.c
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@ -362,7 +362,7 @@ int cap_bprm_set_security (struct linux_binprm *bprm)
* If only the real uid is 0, we do not set the effective
* bit.
*/
if (bprm->e_uid == 0 || current->uid == 0) {
if (bprm->e_uid == 0 || current_uid() == 0) {
/* pP' = (cap_bset & ~0) | (pI & ~0) */
bprm->cap_post_exec_permitted = cap_combine(
current->cap_bset, current->cap_inheritable
@ -379,8 +379,12 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
{
kernel_cap_t pP = current->cap_permitted;
kernel_cap_t pE = current->cap_effective;
uid_t uid;
gid_t gid;
if (bprm->e_uid != current->uid || bprm->e_gid != current->gid ||
current_uid_gid(&uid, &gid);
if (bprm->e_uid != uid || bprm->e_gid != gid ||
!cap_issubset(bprm->cap_post_exec_permitted,
current->cap_permitted)) {
set_dumpable(current->mm, suid_dumpable);
@ -388,8 +392,8 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
if (!capable(CAP_SETUID)) {
bprm->e_uid = current->uid;
bprm->e_gid = current->gid;
bprm->e_uid = uid;
bprm->e_gid = gid;
}
if (cap_limit_ptraced_target()) {
bprm->cap_post_exec_permitted = cap_intersect(
@ -437,15 +441,15 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
int cap_bprm_secureexec (struct linux_binprm *bprm)
{
if (current->uid != 0) {
if (current_uid() != 0) {
if (bprm->cap_effective)
return 1;
if (!cap_isclear(bprm->cap_post_exec_permitted))
return 1;
}
return (current->euid != current->uid ||
current->egid != current->gid);
return (current_euid() != current_uid() ||
current_egid() != current_gid());
}
int cap_inode_setxattr(struct dentry *dentry, const char *name,
@ -508,16 +512,18 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name)
static inline void cap_emulate_setxuid (int old_ruid, int old_euid,
int old_suid)
{
uid_t euid = current_euid();
if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) &&
(current->uid != 0 && current->euid != 0 && current->suid != 0) &&
(current_uid() != 0 && euid != 0 && current_suid() != 0) &&
!issecure(SECURE_KEEP_CAPS)) {
cap_clear (current->cap_permitted);
cap_clear (current->cap_effective);
}
if (old_euid == 0 && current->euid != 0) {
if (old_euid == 0 && euid != 0) {
cap_clear (current->cap_effective);
}
if (old_euid != 0 && current->euid == 0) {
if (old_euid != 0 && euid == 0) {
current->cap_effective = current->cap_permitted;
}
}
@ -546,12 +552,12 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
*/
if (!issecure (SECURE_NO_SETUID_FIXUP)) {
if (old_fsuid == 0 && current->fsuid != 0) {
if (old_fsuid == 0 && current_fsuid() != 0) {
current->cap_effective =
cap_drop_fs_set(
current->cap_effective);
}
if (old_fsuid != 0 && current->fsuid == 0) {
if (old_fsuid != 0 && current_fsuid() == 0) {
current->cap_effective =
cap_raise_fs_set(
current->cap_effective,