*/
#include <linux/capability.h>
+#include <linux/audit.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
* returns 0 when a task has a capability, but the kernel's capable()
* returns 1 for this case.
*/
-int cap_capable (struct task_struct *tsk, int cap)
+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))
#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
-static inline int cap_block_setpcap(struct task_struct *target)
-{
- /*
- * No support for remote process capability manipulation with
- * filesystem capability support.
- */
- return (target != current);
-}
-
static inline int cap_inh_is_capped(void)
{
/*
* to the old permitted set. That is, if the current task
* does *not* possess the CAP_SETPCAP capability.
*/
- return (cap_capable(current, CAP_SETPCAP) != 0);
+ return (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0);
}
static inline int cap_limit_ptraced_target(void) { return 1; }
#else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */
-static inline int cap_block_setpcap(struct task_struct *t) { return 0; }
static inline int cap_inh_is_capped(void) { return 1; }
static inline int cap_limit_ptraced_target(void)
{
#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
-int cap_capset_check (struct task_struct *target, kernel_cap_t *effective,
+int cap_capset_check (kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
- if (cap_block_setpcap(target)) {
- return -EPERM;
- }
if (cap_inh_is_capped()
&& !cap_issubset(*inheritable,
- cap_combine(target->cap_inheritable,
+ cap_combine(current->cap_inheritable,
current->cap_permitted))) {
/* incapable of using this inheritable set */
return -EPERM;
}
if (!cap_issubset(*inheritable,
- cap_combine(target->cap_inheritable,
+ cap_combine(current->cap_inheritable,
current->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 (target->cap_permitted,
+ cap_combine (current->cap_permitted,
current->cap_permitted))) {
return -EPERM;
}
return 0;
}
-void cap_capset_set (struct task_struct *target, kernel_cap_t *effective,
+void cap_capset_set (kernel_cap_t *effective,
kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
- target->cap_effective = *effective;
- target->cap_inheritable = *inheritable;
- target->cap_permitted = *permitted;
+ current->cap_effective = *effective;
+ current->cap_inheritable = *inheritable;
+ current->cap_permitted = *permitted;
}
static inline void bprm_clear_caps(struct linux_binprm *bprm)
return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
}
-static inline int cap_from_disk(struct vfs_cap_data *caps,
- struct linux_binprm *bprm, unsigned size)
+static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
+ struct linux_binprm *bprm)
+{
+ unsigned i;
+ int ret = 0;
+
+ if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
+ bprm->cap_effective = true;
+ else
+ bprm->cap_effective = false;
+
+ CAP_FOR_EACH_U32(i) {
+ __u32 permitted = caps->permitted.cap[i];
+ __u32 inheritable = caps->inheritable.cap[i];
+
+ /*
+ * pP' = (X & fP) | (pI & fI)
+ */
+ bprm->cap_post_exec_permitted.cap[i] =
+ (current->cap_bset.cap[i] & permitted) |
+ (current->cap_inheritable.cap[i] & inheritable);
+
+ if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) {
+ /*
+ * insufficient to execute correctly
+ */
+ ret = -EPERM;
+ }
+ }
+
+ /*
+ * For legacy apps, with no internal support for recognizing they
+ * do not have enough capabilities, we return an error if they are
+ * missing some "forced" (aka file-permitted) capabilities.
+ */
+ return bprm->cap_effective ? ret : 0;
+}
+
+int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
{
+ struct inode *inode = dentry->d_inode;
__u32 magic_etc;
unsigned tocopy, i;
- int ret;
+ int size;
+ struct vfs_cap_data caps;
+
+ memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
+
+ if (!inode || !inode->i_op || !inode->i_op->getxattr)
+ return -ENODATA;
+
+ size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
+ XATTR_CAPS_SZ);
+ if (size == -ENODATA || size == -EOPNOTSUPP) {
+ /* no data, that's ok */
+ return -ENODATA;
+ }
+ if (size < 0)
+ return size;
if (size < sizeof(magic_etc))
return -EINVAL;
- magic_etc = le32_to_cpu(caps->magic_etc);
+ cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
switch ((magic_etc & VFS_CAP_REVISION_MASK)) {
case VFS_CAP_REVISION_1:
return -EINVAL;
}
- if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) {
- bprm->cap_effective = true;
- } else {
- bprm->cap_effective = false;
- }
-
- ret = 0;
-
CAP_FOR_EACH_U32(i) {
- __u32 value_cpu;
-
- if (i >= tocopy) {
- /*
- * Legacy capability sets have no upper bits
- */
- bprm->cap_post_exec_permitted.cap[i] = 0;
- continue;
- }
- /*
- * pP' = (X & fP) | (pI & fI)
- */
- value_cpu = le32_to_cpu(caps->data[i].permitted);
- bprm->cap_post_exec_permitted.cap[i] =
- (current->cap_bset.cap[i] & value_cpu) |
- (current->cap_inheritable.cap[i] &
- le32_to_cpu(caps->data[i].inheritable));
- if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) {
- /*
- * insufficient to execute correctly
- */
- ret = -EPERM;
- }
+ if (i >= tocopy)
+ break;
+ cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
+ cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
}
-
- /*
- * For legacy apps, with no internal support for recognizing they
- * do not have enough capabilities, we return an error if they are
- * missing some "forced" (aka file-permitted) capabilities.
- */
- return bprm->cap_effective ? ret : 0;
+ return 0;
}
/* Locate any VFS capabilities: */
{
struct dentry *dentry;
int rc = 0;
- struct vfs_cap_data vcaps;
- struct inode *inode;
+ struct cpu_vfs_cap_data vcaps;
- if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) {
- bprm_clear_caps(bprm);
+ bprm_clear_caps(bprm);
+
+ if (!file_caps_enabled)
+ return 0;
+
+ if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
return 0;
- }
dentry = dget(bprm->file->f_dentry);
- inode = dentry->d_inode;
- if (!inode->i_op || !inode->i_op->getxattr)
- goto out;
- rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps,
- XATTR_CAPS_SZ);
- if (rc == -ENODATA || rc == -EOPNOTSUPP) {
- /* no data, that's ok */
- rc = 0;
+ rc = get_vfs_caps_from_disk(dentry, &vcaps);
+ if (rc < 0) {
+ if (rc == -EINVAL)
+ printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
+ __func__, rc, bprm->filename);
+ else if (rc == -ENODATA)
+ rc = 0;
goto out;
}
- if (rc < 0)
- goto out;
- rc = cap_from_disk(&vcaps, bprm, rc);
- if (rc == -EINVAL)
- printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
- __func__, rc, bprm->filename);
+ rc = bprm_caps_from_vfs_caps(&vcaps, bprm);
out:
dput(dentry);
* 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
void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
{
- if (bprm->e_uid != current->uid || bprm->e_gid != current->gid ||
+ kernel_cap_t pP = current->cap_permitted;
+ kernel_cap_t pE = current->cap_effective;
+ uid_t uid;
+ gid_t 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);
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(
cap_clear(current->cap_effective);
}
- /* AUD: Audit candidate if current->cap_effective is set */
+ /*
+ * Audit candidate if current->cap_effective is set
+ *
+ * We do not bother to audit if 3 things are true:
+ * 1) cap_effective has all caps
+ * 2) we are root
+ * 3) root is supposed to have all caps (SECURE_NOROOT)
+ * Since this is just a normal root execing a process.
+ *
+ * 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) ||
+ issecure(SECURE_NOROOT))
+ audit_log_bprm_fcaps(bprm, &pP, &pE);
+ }
current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS);
}
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,
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;
}
}
*/
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,
|| ((current->securebits & SECURE_ALL_LOCKS
& ~arg2)) /*[2]*/
|| (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
- || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/
+ || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0)) { /*[4]*/
/*
* [1] no changing of bits that are locked
* [2] no unlocking of locks
{
int cap_sys_admin = 0;
- if (cap_capable(current, CAP_SYS_ADMIN) == 0)
+ if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0)
cap_sys_admin = 1;
return __vm_enough_memory(mm, pages, cap_sys_admin);
}
projects / linux-block.git / blobdiff