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authorDavid Howells <dhowells@redhat.com>2008-11-14 10:39:16 +1100
committerJames Morris <jmorris@namei.org>2008-11-14 10:39:16 +1100
commitb6dff3ec5e116e3af6f537d4caedcad6b9e5082a (patch)
tree9e76f972eb7ce9b84e0146c8e4126a3f86acb428 /security/commoncap.c
parent15a2460ed0af7538ca8e6c610fe607a2cd9da142 (diff)
downloadlinux-b6dff3ec5e116e3af6f537d4caedcad6b9e5082a.tar.gz
CRED: Separate task security context from task_struct
Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/commoncap.c')
-rw-r--r--security/commoncap.c161
1 files changed, 85 insertions, 76 deletions
diff --git a/security/commoncap.c b/security/commoncap.c
index fb4e240720d..fa61679f8c7 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -30,7 +30,7 @@
int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
{
- NETLINK_CB(skb).eff_cap = current->cap_effective;
+ NETLINK_CB(skb).eff_cap = current_cap();
return 0;
}
@@ -52,7 +52,7 @@ EXPORT_SYMBOL(cap_netlink_recv);
int cap_capable(struct task_struct *tsk, int cap, int audit)
{
/* Derived from include/linux/sched.h:capable. */
- if (cap_raised(tsk->cap_effective, cap))
+ if (cap_raised(tsk->cred->cap_effective, cap))
return 0;
return -EPERM;
}
@@ -67,7 +67,8 @@ int cap_settime(struct timespec *ts, struct timezone *tz)
int cap_ptrace_may_access(struct task_struct *child, unsigned int mode)
{
/* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */
- if (cap_issubset(child->cap_permitted, current->cap_permitted))
+ if (cap_issubset(child->cred->cap_permitted,
+ current->cred->cap_permitted))
return 0;
if (capable(CAP_SYS_PTRACE))
return 0;
@@ -76,8 +77,8 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode)
int cap_ptrace_traceme(struct task_struct *parent)
{
- /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */
- if (cap_issubset(current->cap_permitted, parent->cap_permitted))
+ if (cap_issubset(current->cred->cap_permitted,
+ parent->cred->cap_permitted))
return 0;
if (has_capability(parent, CAP_SYS_PTRACE))
return 0;
@@ -87,10 +88,12 @@ int cap_ptrace_traceme(struct task_struct *parent)
int cap_capget (struct task_struct *target, kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
+ struct cred *cred = target->cred;
+
/* Derived from kernel/capability.c:sys_capget. */
- *effective = target->cap_effective;
- *inheritable = target->cap_inheritable;
- *permitted = target->cap_permitted;
+ *effective = cred->cap_effective;
+ *inheritable = cred->cap_inheritable;
+ *permitted = cred->cap_permitted;
return 0;
}
@@ -122,24 +125,26 @@ int cap_capset_check(const kernel_cap_t *effective,
const kernel_cap_t *inheritable,
const kernel_cap_t *permitted)
{
+ const struct cred *cred = current->cred;
+
if (cap_inh_is_capped()
&& !cap_issubset(*inheritable,
- cap_combine(current->cap_inheritable,
- current->cap_permitted))) {
+ cap_combine(cred->cap_inheritable,
+ cred->cap_permitted))) {
/* incapable of using this inheritable set */
return -EPERM;
}
if (!cap_issubset(*inheritable,
- cap_combine(current->cap_inheritable,
- current->cap_bset))) {
+ cap_combine(cred->cap_inheritable,
+ cred->cap_bset))) {
/* no new pI capabilities outside bounding set */
return -EPERM;
}
/* verify restrictions on target's new Permitted set */
if (!cap_issubset (*permitted,
- cap_combine (current->cap_permitted,
- current->cap_permitted))) {
+ cap_combine (cred->cap_permitted,
+ cred->cap_permitted))) {
return -EPERM;
}
@@ -155,9 +160,11 @@ void cap_capset_set(const kernel_cap_t *effective,
const kernel_cap_t *inheritable,
const kernel_cap_t *permitted)
{
- current->cap_effective = *effective;
- current->cap_inheritable = *inheritable;
- current->cap_permitted = *permitted;
+ struct cred *cred = current->cred;
+
+ cred->cap_effective = *effective;
+ cred->cap_inheritable = *inheritable;
+ cred->cap_permitted = *permitted;
}
static inline void bprm_clear_caps(struct linux_binprm *bprm)
@@ -211,8 +218,8 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
* pP' = (X & fP) | (pI & fI)
*/
bprm->cap_post_exec_permitted.cap[i] =
- (current->cap_bset.cap[i] & permitted) |
- (current->cap_inheritable.cap[i] & inheritable);
+ (current->cred->cap_bset.cap[i] & permitted) |
+ (current->cred->cap_inheritable.cap[i] & inheritable);
if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) {
/*
@@ -354,8 +361,8 @@ int cap_bprm_set_security (struct linux_binprm *bprm)
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
- );
+ current->cred->cap_bset,
+ current->cred->cap_inheritable);
bprm->cap_effective = (bprm->e_uid == 0);
ret = 0;
}
@@ -366,44 +373,39 @@ int cap_bprm_set_security (struct linux_binprm *bprm)
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;
+ struct cred *cred = current->cred;
- current_uid_gid(&uid, &gid);
-
- if (bprm->e_uid != uid || bprm->e_gid != gid ||
+ if (bprm->e_uid != cred->uid || bprm->e_gid != cred->gid ||
!cap_issubset(bprm->cap_post_exec_permitted,
- current->cap_permitted)) {
+ cred->cap_permitted)) {
set_dumpable(current->mm, suid_dumpable);
current->pdeath_signal = 0;
if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
if (!capable(CAP_SETUID)) {
- bprm->e_uid = uid;
- bprm->e_gid = gid;
+ bprm->e_uid = cred->uid;
+ bprm->e_gid = cred->gid;
}
if (cap_limit_ptraced_target()) {
bprm->cap_post_exec_permitted = cap_intersect(
bprm->cap_post_exec_permitted,
- current->cap_permitted);
+ cred->cap_permitted);
}
}
}
- current->suid = current->euid = current->fsuid = bprm->e_uid;
- current->sgid = current->egid = current->fsgid = bprm->e_gid;
+ cred->suid = cred->euid = cred->fsuid = bprm->e_uid;
+ cred->sgid = cred->egid = cred->fsgid = bprm->e_gid;
/* For init, we want to retain the capabilities set
* in the init_task struct. Thus we skip the usual
* capability rules */
if (!is_global_init(current)) {
- current->cap_permitted = bprm->cap_post_exec_permitted;
+ cred->cap_permitted = bprm->cap_post_exec_permitted;
if (bprm->cap_effective)
- current->cap_effective = bprm->cap_post_exec_permitted;
+ cred->cap_effective = bprm->cap_post_exec_permitted;
else
- cap_clear(current->cap_effective);
+ cap_clear(cred->cap_effective);
}
/*
@@ -418,27 +420,30 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
* Number 1 above might fail if you don't have a full bset, but I think
* that is interesting information to audit.
*/
- if (!cap_isclear(current->cap_effective)) {
- if (!cap_issubset(CAP_FULL_SET, current->cap_effective) ||
- (bprm->e_uid != 0) || (current->uid != 0) ||
+ if (!cap_isclear(cred->cap_effective)) {
+ if (!cap_issubset(CAP_FULL_SET, cred->cap_effective) ||
+ (bprm->e_uid != 0) || (cred->uid != 0) ||
issecure(SECURE_NOROOT))
- audit_log_bprm_fcaps(bprm, &pP, &pE);
+ audit_log_bprm_fcaps(bprm, &cred->cap_permitted,
+ &cred->cap_effective);
}
- current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
+ cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
}
int cap_bprm_secureexec (struct linux_binprm *bprm)
{
- if (current_uid() != 0) {
+ const struct cred *cred = current->cred;
+
+ if (cred->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 (cred->euid != cred->uid ||
+ cred->egid != cred->gid);
}
int cap_inode_setxattr(struct dentry *dentry, const char *name,
@@ -501,25 +506,27 @@ 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();
+ struct cred *cred = current->cred;
if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) &&
- (current_uid() != 0 && euid != 0 && current_suid() != 0) &&
+ (cred->uid != 0 && cred->euid != 0 && cred->suid != 0) &&
!issecure(SECURE_KEEP_CAPS)) {
- cap_clear (current->cap_permitted);
- cap_clear (current->cap_effective);
+ cap_clear (cred->cap_permitted);
+ cap_clear (cred->cap_effective);
}
- if (old_euid == 0 && euid != 0) {
- cap_clear (current->cap_effective);
+ if (old_euid == 0 && cred->euid != 0) {
+ cap_clear (cred->cap_effective);
}
- if (old_euid != 0 && euid == 0) {
- current->cap_effective = current->cap_permitted;
+ if (old_euid != 0 && cred->euid == 0) {
+ cred->cap_effective = cred->cap_permitted;
}
}
int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
int flags)
{
+ struct cred *cred = current->cred;
+
switch (flags) {
case LSM_SETID_RE:
case LSM_SETID_ID:
@@ -541,16 +548,16 @@ 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) {
- current->cap_effective =
+ if (old_fsuid == 0 && cred->fsuid != 0) {
+ cred->cap_effective =
cap_drop_fs_set(
- current->cap_effective);
+ cred->cap_effective);
}
- if (old_fsuid != 0 && current_fsuid() == 0) {
- current->cap_effective =
+ if (old_fsuid != 0 && cred->fsuid == 0) {
+ cred->cap_effective =
cap_raise_fs_set(
- current->cap_effective,
- current->cap_permitted);
+ cred->cap_effective,
+ cred->cap_permitted);
}
}
break;
@@ -575,7 +582,8 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
*/
static int cap_safe_nice(struct task_struct *p)
{
- if (!cap_issubset(p->cap_permitted, current->cap_permitted) &&
+ if (!cap_issubset(p->cred->cap_permitted,
+ current->cred->cap_permitted) &&
!capable(CAP_SYS_NICE))
return -EPERM;
return 0;
@@ -610,7 +618,7 @@ static long cap_prctl_drop(unsigned long cap)
return -EPERM;
if (!cap_valid(cap))
return -EINVAL;
- cap_lower(current->cap_bset, cap);
+ cap_lower(current->cred->cap_bset, cap);
return 0;
}
@@ -633,6 +641,7 @@ int cap_task_setnice (struct task_struct *p, int nice)
int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
unsigned long arg4, unsigned long arg5, long *rc_p)
{
+ struct cred *cred = current->cred;
long error = 0;
switch (option) {
@@ -640,7 +649,7 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
if (!cap_valid(arg2))
error = -EINVAL;
else
- error = !!cap_raised(current->cap_bset, arg2);
+ error = !!cap_raised(cred->cap_bset, arg2);
break;
#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
case PR_CAPBSET_DROP:
@@ -667,9 +676,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
* capability-based-privilege environment.
*/
case PR_SET_SECUREBITS:
- if ((((current->securebits & SECURE_ALL_LOCKS) >> 1)
- & (current->securebits ^ arg2)) /*[1]*/
- || ((current->securebits & SECURE_ALL_LOCKS
+ if ((((cred->securebits & SECURE_ALL_LOCKS) >> 1)
+ & (cred->securebits ^ arg2)) /*[1]*/
+ || ((cred->securebits & SECURE_ALL_LOCKS
& ~arg2)) /*[2]*/
|| (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
|| (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/
@@ -682,11 +691,11 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
*/
error = -EPERM; /* cannot change a locked bit */
} else {
- current->securebits = arg2;
+ cred->securebits = arg2;
}
break;
case PR_GET_SECUREBITS:
- error = current->securebits;
+ error = cred->securebits;
break;
#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
@@ -701,10 +710,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
else if (issecure(SECURE_KEEP_CAPS_LOCKED))
error = -EPERM;
else if (arg2)
- current->securebits |= issecure_mask(SECURE_KEEP_CAPS);
+ cred->securebits |= issecure_mask(SECURE_KEEP_CAPS);
else
- current->securebits &=
- ~issecure_mask(SECURE_KEEP_CAPS);
+ cred->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
break;
default:
@@ -719,11 +727,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
void cap_task_reparent_to_init (struct task_struct *p)
{
- cap_set_init_eff(p->cap_effective);
- cap_clear(p->cap_inheritable);
- cap_set_full(p->cap_permitted);
- p->securebits = SECUREBITS_DEFAULT;
- return;
+ struct cred *cred = p->cred;
+
+ cap_set_init_eff(cred->cap_effective);
+ cap_clear(cred->cap_inheritable);
+ cap_set_full(cred->cap_permitted);
+ p->cred->securebits = SECUREBITS_DEFAULT;
}
int cap_syslog (int type)