nfsd: nfsd should drop CAP_MKNOD for non-root

[safe/jmp/linux-2.6] / fs / binfmt_elf.c

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index e215906..33b7235 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -152,12 +152,14 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
        elf_addr_t __user *sp;
        elf_addr_t __user *u_platform;
        elf_addr_t __user *u_base_platform;
+       elf_addr_t __user *u_rand_bytes;
        const char *k_platform = ELF_PLATFORM;
        const char *k_base_platform = ELF_BASE_PLATFORM;
+       unsigned char k_rand_bytes[16];
        int items;
        elf_addr_t *elf_info;
        int ei_index = 0;
-       struct task_struct *tsk = current;
+       const struct cred *cred = current_cred();
        struct vm_area_struct *vma;
 
        /*
@@ -196,6 +198,15 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
                        return -EFAULT;
        }
 
+       /*
+        * Generate 16 random bytes for userspace PRNG seeding.
+        */
+       get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
+       u_rand_bytes = (elf_addr_t __user *)
+                      STACK_ALLOC(p, sizeof(k_rand_bytes));
+       if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
+               return -EFAULT;
+
        /* Create the ELF interpreter info */
        elf_info = (elf_addr_t *)current->mm->saved_auxv;
        /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
@@ -223,11 +234,12 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
        NEW_AUX_ENT(AT_BASE, interp_load_addr);
        NEW_AUX_ENT(AT_FLAGS, 0);
        NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
-       NEW_AUX_ENT(AT_UID, tsk->uid);
-       NEW_AUX_ENT(AT_EUID, tsk->euid);
-       NEW_AUX_ENT(AT_GID, tsk->gid);
-       NEW_AUX_ENT(AT_EGID, tsk->egid);
+       NEW_AUX_ENT(AT_UID, cred->uid);
+       NEW_AUX_ENT(AT_EUID, cred->euid);
+       NEW_AUX_ENT(AT_GID, cred->gid);
+       NEW_AUX_ENT(AT_EGID, cred->egid);
        NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
+       NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
        NEW_AUX_ENT(AT_EXECFN, bprm->exec);
        if (k_platform) {
                NEW_AUX_ENT(AT_PLATFORM,
@@ -949,14 +961,14 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
        set_binfmt(&elf_format);
 
 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
-       retval = arch_setup_additional_pages(bprm, executable_stack);
+       retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
        if (retval < 0) {
                send_sig(SIGKILL, current, 0);
                goto out;
        }
 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
 
-       compute_creds(bprm);
+       install_exec_creds(bprm);
        current->flags &= ~PF_FORKNOEXEC;
        retval = create_elf_tables(bprm, &loc->elf_ex,
                          load_addr, interp_load_addr);
@@ -1196,9 +1208,11 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
         * check for an ELF header.  If we find one, dump the first page to
         * aid in determining what was mapped here.
         */
-       if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
+       if (FILTER(ELF_HEADERS) &&
+           vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
                u32 __user *header = (u32 __user *) vma->vm_start;
                u32 word;
+               mm_segment_t fs = get_fs();
                /*
                 * Doing it this way gets the constant folded by GCC.
                 */
@@ -1211,7 +1225,15 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
                magic.elfmag[EI_MAG1] = ELFMAG1;
                magic.elfmag[EI_MAG2] = ELFMAG2;
                magic.elfmag[EI_MAG3] = ELFMAG3;
-               if (get_user(word, header) == 0 && word == magic.cmp)
+               /*
+                * Switch to the user "segment" for get_user(),
+                * then put back what elf_core_dump() had in place.
+                */
+               set_fs(USER_DS);
+               if (unlikely(get_user(word, header)))
+                       word = 0;
+               set_fs(fs);
+               if (word == magic.cmp)
                        return PAGE_SIZE;
        }
 
@@ -1341,20 +1363,15 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
        prstatus->pr_pgrp = task_pgrp_vnr(p);
        prstatus->pr_sid = task_session_vnr(p);
        if (thread_group_leader(p)) {
+               struct task_cputime cputime;
+
                /*
-                * This is the record for the group leader.  Add in the
-                * cumulative times of previous dead threads.  This total
-                * won't include the time of each live thread whose state
-                * is included in the core dump.  The final total reported
-                * to our parent process when it calls wait4 will include
-                * those sums as well as the little bit more time it takes
-                * this and each other thread to finish dying after the
-                * core dump synchronization phase.
+                * This is the record for the group leader.  It shows the
+                * group-wide total, not its individual thread total.
                 */
-               cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
-                                  &prstatus->pr_utime);
-               cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
-                                  &prstatus->pr_stime);
+               thread_group_cputime(p, &cputime);
+               cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
+               cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
        } else {
                cputime_to_timeval(p->utime, &prstatus->pr_utime);
                cputime_to_timeval(p->stime, &prstatus->pr_stime);
@@ -1366,6 +1383,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
                       struct mm_struct *mm)
 {
+       const struct cred *cred;
        unsigned int i, len;
        
        /* first copy the parameters from user space */
@@ -1393,8 +1411,11 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
        psinfo->pr_nice = task_nice(p);
        psinfo->pr_flag = p->flags;
-       SET_UID(psinfo->pr_uid, p->uid);
-       SET_GID(psinfo->pr_gid, p->gid);
+       rcu_read_lock();
+       cred = __task_cred(p);
+       SET_UID(psinfo->pr_uid, cred->uid);
+       SET_GID(psinfo->pr_gid, cred->gid);
+       rcu_read_unlock();
        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
        
        return 0;