Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 345 insertions, 0 deletions

diff --git a/security/commoncap.c b/security/commoncap.c
new file mode 100644
index 000000000000..849b8c338ee8
--- /dev/null
+++ b/security/commoncap.c
@@ -0,0 +1,345 @@
+/* Common capabilities, needed by capability.o and root_plug.o 
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/security.h>
+#include <linux/file.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/smp_lock.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/ptrace.h>
+#include <linux/xattr.h>
+#include <linux/hugetlb.h>
+
+int cap_netlink_send(struct sock *sk, struct sk_buff *skb)
+{
+        NETLINK_CB(skb).eff_cap = current->cap_effective;
+        return 0;
+}
+
+EXPORT_SYMBOL(cap_netlink_send);
+
+int cap_netlink_recv(struct sk_buff *skb)
+{
+        if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
+                return -EPERM;
+        return 0;
+}
+
+EXPORT_SYMBOL(cap_netlink_recv);
+
+int cap_capable (struct task_struct *tsk, int cap)
+{
+        /* Derived from include/linux/sched.h:capable. */
+        if (cap_raised(tsk->cap_effective, cap))
+                return 0;
+        return -EPERM;
+}
+
+int cap_settime(struct timespec *ts, struct timezone *tz)
+{
+        if (!capable(CAP_SYS_TIME))
+                return -EPERM;
+        return 0;
+}
+
+int cap_ptrace (struct task_struct *parent, struct task_struct *child)
+{
+        /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */
+        if (!cap_issubset (child->cap_permitted, current->cap_permitted) &&
+            !capable(CAP_SYS_PTRACE))
+                return -EPERM;
+        return 0;
+}
+
+int cap_capget (struct task_struct *target, kernel_cap_t *effective,
+                kernel_cap_t *inheritable, kernel_cap_t *permitted)
+{
+        /* Derived from kernel/capability.c:sys_capget. */
+        *effective = cap_t (target->cap_effective);
+        *inheritable = cap_t (target->cap_inheritable);
+        *permitted = cap_t (target->cap_permitted);
+        return 0;
+}
+
+int cap_capset_check (struct task_struct *target, kernel_cap_t *effective,
+                      kernel_cap_t *inheritable, kernel_cap_t *permitted)
+{
+        /* Derived from kernel/capability.c:sys_capset. */
+        /* verify restrictions on target's new Inheritable set */
+        if (!cap_issubset (*inheritable,
+                           cap_combine (target->cap_inheritable,
+                                        current->cap_permitted))) {
+                return -EPERM;
+        }
+
+        /* verify restrictions on target's new Permitted set */
+        if (!cap_issubset (*permitted,
+                           cap_combine (target->cap_permitted,
+                                        current->cap_permitted))) {
+                return -EPERM;
+        }
+
+        /* verify the _new_Effective_ is a subset of the _new_Permitted_ */
+        if (!cap_issubset (*effective, *permitted)) {
+                return -EPERM;
+        }
+
+        return 0;
+}
+
+void cap_capset_set (struct task_struct *target, kernel_cap_t *effective,
+                     kernel_cap_t *inheritable, kernel_cap_t *permitted)
+{
+        target->cap_effective = *effective;
+        target->cap_inheritable = *inheritable;
+        target->cap_permitted = *permitted;
+}
+
+int cap_bprm_set_security (struct linux_binprm *bprm)
+{
+        /* Copied from fs/exec.c:prepare_binprm. */
+
+        /* We don't have VFS support for capabilities yet */
+        cap_clear (bprm->cap_inheritable);
+        cap_clear (bprm->cap_permitted);
+        cap_clear (bprm->cap_effective);
+
+        /*  To support inheritance of root-permissions and suid-root
+         *  executables under compatibility mode, we raise all three
+         *  capability sets for the file.
+         *
+         *  If only the real uid is 0, we only raise the inheritable
+         *  and permitted sets of the executable file.
+         */
+
+        if (!issecure (SECURE_NOROOT)) {
+                if (bprm->e_uid == 0 || current->uid == 0) {
+                        cap_set_full (bprm->cap_inheritable);
+                        cap_set_full (bprm->cap_permitted);
+                }
+                if (bprm->e_uid == 0)
+                        cap_set_full (bprm->cap_effective);
+        }
+        return 0;
+}
+
+void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
+{
+        /* Derived from fs/exec.c:compute_creds. */
+        kernel_cap_t new_permitted, working;
+
+        new_permitted = cap_intersect (bprm->cap_permitted, cap_bset);
+        working = cap_intersect (bprm->cap_inheritable,
+                                 current->cap_inheritable);
+        new_permitted = cap_combine (new_permitted, working);
+
+        if (bprm->e_uid != current->uid || bprm->e_gid != current->gid ||
+            !cap_issubset (new_permitted, current->cap_permitted)) {
+                current->mm->dumpable = 0;
+
+                if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
+                        if (!capable(CAP_SETUID)) {
+                                bprm->e_uid = current->uid;
+                                bprm->e_gid = current->gid;
+                        }
+                        if (!capable (CAP_SETPCAP)) {
+                                new_permitted = cap_intersect (new_permitted,
+                                                        current->cap_permitted);
+                        }
+                }
+        }
+
+        current->suid = current->euid = current->fsuid = bprm->e_uid;
+        current->sgid = current->egid = current->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 (current->pid != 1) {
+                current->cap_permitted = new_permitted;
+                current->cap_effective =
+                    cap_intersect (new_permitted, bprm->cap_effective);
+        }
+
+        /* AUD: Audit candidate if current->cap_effective is set */
+
+        current->keep_capabilities = 0;
+}
+
+int cap_bprm_secureexec (struct linux_binprm *bprm)
+{
+        /* If/when this module is enhanced to incorporate capability
+           bits on files, the test below should be extended to also perform a 
+           test between the old and new capability sets.  For now,
+           it simply preserves the legacy decision algorithm used by
+           the old userland. */
+        return (current->euid != current->uid ||
+                current->egid != current->gid);
+}
+
+int cap_inode_setxattr(struct dentry *dentry, char *name, void *value,
+                       size_t size, int flags)
+{
+        if (!strncmp(name, XATTR_SECURITY_PREFIX,
+                     sizeof(XATTR_SECURITY_PREFIX) - 1)  &&
+            !capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        return 0;
+}
+
+int cap_inode_removexattr(struct dentry *dentry, char *name)
+{
+        if (!strncmp(name, XATTR_SECURITY_PREFIX,
+                     sizeof(XATTR_SECURITY_PREFIX) - 1)  &&
+            !capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        return 0;
+}
+
+/* moved from kernel/sys.c. */
+/* 
+ * cap_emulate_setxuid() fixes the effective / permitted capabilities of
+ * a process after a call to setuid, setreuid, or setresuid.
+ *
+ *  1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of
+ *  {r,e,s}uid != 0, the permitted and effective capabilities are
+ *  cleared.
+ *
+ *  2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective
+ *  capabilities of the process are cleared.
+ *
+ *  3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective
+ *  capabilities are set to the permitted capabilities.
+ *
+ *  fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should 
+ *  never happen.
+ *
+ *  -astor 
+ *
+ * cevans - New behaviour, Oct '99
+ * A process may, via prctl(), elect to keep its capabilities when it
+ * calls setuid() and switches away from uid==0. Both permitted and
+ * effective sets will be retained.
+ * Without this change, it was impossible for a daemon to drop only some
+ * of its privilege. The call to setuid(!=0) would drop all privileges!
+ * Keeping uid 0 is not an option because uid 0 owns too many vital
+ * files..
+ * Thanks to Olaf Kirch and Peter Benie for spotting this.
+ */
+static inline void cap_emulate_setxuid (int old_ruid, int old_euid,
+                                        int old_suid)
+{
+        if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) &&
+            (current->uid != 0 && current->euid != 0 && current->suid != 0) &&
+            !current->keep_capabilities) {
+                cap_clear (current->cap_permitted);
+                cap_clear (current->cap_effective);
+        }
+        if (old_euid == 0 && current->euid != 0) {
+                cap_clear (current->cap_effective);
+        }
+        if (old_euid != 0 && current->euid == 0) {
+                current->cap_effective = current->cap_permitted;
+        }
+}
+
+int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
+                          int flags)
+{
+        switch (flags) {
+        case LSM_SETID_RE:
+        case LSM_SETID_ID:
+        case LSM_SETID_RES:
+                /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */
+                if (!issecure (SECURE_NO_SETUID_FIXUP)) {
+                        cap_emulate_setxuid (old_ruid, old_euid, old_suid);
+                }
+                break;
+        case LSM_SETID_FS:
+                {
+                        uid_t old_fsuid = old_ruid;
+
+                        /* Copied from kernel/sys.c:setfsuid. */
+
+                        /*
+                         * FIXME - is fsuser used for all CAP_FS_MASK capabilities?
+                         *          if not, we might be a bit too harsh here.
+                         */
+
+                        if (!issecure (SECURE_NO_SETUID_FIXUP)) {
+                                if (old_fsuid == 0 && current->fsuid != 0) {
+                                        cap_t (current->cap_effective) &=
+                                            ~CAP_FS_MASK;
+                                }
+                                if (old_fsuid != 0 && current->fsuid == 0) {
+                                        cap_t (current->cap_effective) |=
+                                            (cap_t (current->cap_permitted) &
+                                             CAP_FS_MASK);
+                                }
+                        }
+                        break;
+                }
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+void cap_task_reparent_to_init (struct task_struct *p)
+{
+        p->cap_effective = CAP_INIT_EFF_SET;
+        p->cap_inheritable = CAP_INIT_INH_SET;
+        p->cap_permitted = CAP_FULL_SET;
+        p->keep_capabilities = 0;
+        return;
+}
+
+int cap_syslog (int type)
+{
+        if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN))
+                return -EPERM;
+        return 0;
+}
+
+int cap_vm_enough_memory(long pages)
+{
+        int cap_sys_admin = 0;
+
+        if (cap_capable(current, CAP_SYS_ADMIN) == 0)
+                cap_sys_admin = 1;
+        return __vm_enough_memory(pages, cap_sys_admin);
+}
+
+EXPORT_SYMBOL(cap_capable);
+EXPORT_SYMBOL(cap_settime);
+EXPORT_SYMBOL(cap_ptrace);
+EXPORT_SYMBOL(cap_capget);
+EXPORT_SYMBOL(cap_capset_check);
+EXPORT_SYMBOL(cap_capset_set);
+EXPORT_SYMBOL(cap_bprm_set_security);
+EXPORT_SYMBOL(cap_bprm_apply_creds);
+EXPORT_SYMBOL(cap_bprm_secureexec);
+EXPORT_SYMBOL(cap_inode_setxattr);
+EXPORT_SYMBOL(cap_inode_removexattr);
+EXPORT_SYMBOL(cap_task_post_setuid);
+EXPORT_SYMBOL(cap_task_reparent_to_init);
+EXPORT_SYMBOL(cap_syslog);
+EXPORT_SYMBOL(cap_vm_enough_memory);
+
+MODULE_DESCRIPTION("Standard Linux Common Capabilities Security Module");
+MODULE_LICENSE("GPL");