1 files changed, 74 insertions, 43 deletions

diff --git a/fs/exec.c b/fs/exec.c
index d49be6bc1793..cce6bbdbdbb1 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -46,7 +46,6 @@
 #include <linux/proc_fs.h>
 #include <linux/mount.h>
 #include <linux/security.h>
-#include <linux/ima.h>
 #include <linux/syscalls.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
@@ -572,6 +571,9 @@ int setup_arg_pages(struct linux_binprm *bprm,
         struct vm_area_struct *prev = NULL;
         unsigned long vm_flags;
         unsigned long stack_base;
+        unsigned long stack_size;
+        unsigned long stack_expand;
+        unsigned long rlim_stack;
 
 #ifdef CONFIG_STACK_GROWSUP
         /* Limit stack size to 1GB */
@@ -624,16 +626,27 @@ int setup_arg_pages(struct linux_binprm *bprm,
         /* Move stack pages down in memory. */
         if (stack_shift) {
                 ret = shift_arg_pages(vma, stack_shift);
-                if (ret) {
-                        up_write(&mm->mmap_sem);
-                        return ret;
-                }
+                if (ret)
+                        goto out_unlock;
         }
 
+        stack_expand = EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        stack_size = vma->vm_end - vma->vm_start;
+        /*
+         * Align this down to a page boundary as expand_stack
+         * will align it up.
+         */
+        rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK;
 #ifdef CONFIG_STACK_GROWSUP
-        stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        if (stack_size + stack_expand > rlim_stack)
+                stack_base = vma->vm_start + rlim_stack;
+        else
+                stack_base = vma->vm_end + stack_expand;
 #else
-        stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE;
+        if (stack_size + stack_expand > rlim_stack)
+                stack_base = vma->vm_end - rlim_stack;
+        else
+                stack_base = vma->vm_start - stack_expand;
 #endif
         ret = expand_stack(vma, stack_base);
         if (ret)
@@ -641,7 +654,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
 
 out_unlock:
         up_write(&mm->mmap_sem);
-        return 0;
+        return ret;
 }
 EXPORT_SYMBOL(setup_arg_pages);
 
@@ -829,7 +842,9 @@ static int de_thread(struct task_struct *tsk)
                 attach_pid(tsk, PIDTYPE_PID,  task_pid(leader));
                 transfer_pid(leader, tsk, PIDTYPE_PGID);
                 transfer_pid(leader, tsk, PIDTYPE_SID);
+
                 list_replace_rcu(&leader->tasks, &tsk->tasks);
+                list_replace_init(&leader->sibling, &tsk->sibling);
 
                 tsk->group_leader = tsk;
                 leader->group_leader = tsk;
@@ -926,6 +941,15 @@ char *get_task_comm(char *buf, struct task_struct *tsk)
 void set_task_comm(struct task_struct *tsk, char *buf)
 {
         task_lock(tsk);
+
+        /*
+         * Threads may access current->comm without holding
+         * the task lock, so write the string carefully.
+         * Readers without a lock may see incomplete new
+         * names but are safe from non-terminating string reads.
+         */
+        memset(tsk->comm, 0, TASK_COMM_LEN);
+        wmb();
         strlcpy(tsk->comm, buf, sizeof(tsk->comm));
         task_unlock(tsk);
         perf_event_comm(tsk);
@@ -933,9 +957,7 @@ void set_task_comm(struct task_struct *tsk, char *buf)
 
 int flush_old_exec(struct linux_binprm * bprm)
 {
-        char * name;
-        int i, ch, retval;
-        char tcomm[sizeof(current->comm)];
+        int retval;
 
         /*
          * Make sure we have a private signal table and that
@@ -956,6 +978,25 @@ int flush_old_exec(struct linux_binprm * bprm)
 
         bprm->mm = NULL;                /* We're using it now */
 
+        current->flags &= ~PF_RANDOMIZE;
+        flush_thread();
+        current->personality &= ~bprm->per_clear;
+
+        return 0;
+
+out:
+        return retval;
+}
+EXPORT_SYMBOL(flush_old_exec);
+
+void setup_new_exec(struct linux_binprm * bprm)
+{
+        int i, ch;
+        char * name;
+        char tcomm[sizeof(current->comm)];
+
+        arch_pick_mmap_layout(current->mm);
+
         /* This is the point of no return */
         current->sas_ss_sp = current->sas_ss_size = 0;
 
@@ -977,9 +1018,6 @@ int flush_old_exec(struct linux_binprm * bprm)
         tcomm[i] = '\0';
         set_task_comm(current, tcomm);
 
-        current->flags &= ~PF_RANDOMIZE;
-        flush_thread();
-
         /* Set the new mm task size. We have to do that late because it may
          * depend on TIF_32BIT which is only updated in flush_thread() on
          * some architectures like powerpc
@@ -995,8 +1033,6 @@ int flush_old_exec(struct linux_binprm * bprm)
                 set_dumpable(current->mm, suid_dumpable);
         }
 
-        current->personality &= ~bprm->per_clear;
-
         /*
          * Flush performance counters when crossing a
          * security domain:
@@ -1011,14 +1047,8 @@ int flush_old_exec(struct linux_binprm * bprm)
                         
         flush_signal_handlers(current, 0);
         flush_old_files(current->files);
-
-        return 0;
-
-out:
-        return retval;
 }
-
-EXPORT_SYMBOL(flush_old_exec);
+EXPORT_SYMBOL(setup_new_exec);
 
 /*
  * Prepare credentials and lock ->cred_guard_mutex.
@@ -1211,9 +1241,6 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
         retval = security_bprm_check(bprm);
         if (retval)
                 return retval;
-        retval = ima_bprm_check(bprm);
-        if (retval)
-                return retval;
 
         /* kernel module loader fixup */
         /* so we don't try to load run modprobe in kernel space. */
@@ -1758,17 +1785,20 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
         struct mm_struct *mm = current->mm;
         struct linux_binfmt * binfmt;
         struct inode * inode;
-        struct file * file;
         const struct cred *old_cred;
         struct cred *cred;
         int retval = 0;
         int flag = 0;
         int ispipe = 0;
-        unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
         char **helper_argv = NULL;
         int helper_argc = 0;
         int dump_count = 0;
         static atomic_t core_dump_count = ATOMIC_INIT(0);
+        struct coredump_params cprm = {
+                .signr = signr,
+                .regs = regs,
+                .limit = current->signal->rlim[RLIMIT_CORE].rlim_cur,
+        };
 
         audit_core_dumps(signr);
 
@@ -1824,15 +1854,15 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
         ispipe = format_corename(corename, signr);
         unlock_kernel();
 
-        if ((!ispipe) && (core_limit < binfmt->min_coredump))
+        if ((!ispipe) && (cprm.limit < binfmt->min_coredump))
                 goto fail_unlock;
 
         if (ispipe) {
-                if (core_limit == 0) {
+                if (cprm.limit == 0) {
                         /*
                          * Normally core limits are irrelevant to pipes, since
                          * we're not writing to the file system, but we use
-                         * core_limit of 0 here as a speacial value. Any
+                         * cprm.limit of 0 here as a speacial value. Any
                          * non-zero limit gets set to RLIM_INFINITY below, but
                          * a limit of 0 skips the dump.  This is a consistent
                          * way to catch recursive crashes.  We can still crash
@@ -1865,25 +1895,25 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
                         goto fail_dropcount;
                 }
 
-                core_limit = RLIM_INFINITY;
+                cprm.limit = RLIM_INFINITY;
 
                 /* SIGPIPE can happen, but it's just never processed */
                 if (call_usermodehelper_pipe(helper_argv[0], helper_argv, NULL,
-                                &file)) {
+                                &cprm.file)) {
                         printk(KERN_INFO "Core dump to %s pipe failed\n",
                                corename);
                         goto fail_dropcount;
                 }
         } else
-                file = filp_open(corename,
+                cprm.file = filp_open(corename,
                                  O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
                                  0600);
-        if (IS_ERR(file))
+        if (IS_ERR(cprm.file))
                 goto fail_dropcount;
-        inode = file->f_path.dentry->d_inode;
+        inode = cprm.file->f_path.dentry->d_inode;
         if (inode->i_nlink > 1)
                 goto close_fail;        /* multiple links - don't dump */
-        if (!ispipe && d_unhashed(file->f_path.dentry))
+        if (!ispipe && d_unhashed(cprm.file->f_path.dentry))
                 goto close_fail;
 
         /* AK: actually i see no reason to not allow this for named pipes etc.,
@@ -1896,21 +1926,22 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
          */
         if (inode->i_uid != current_fsuid())
                 goto close_fail;
-        if (!file->f_op)
+        if (!cprm.file->f_op)
                 goto close_fail;
-        if (!file->f_op->write)
+        if (!cprm.file->f_op->write)
                 goto close_fail;
-        if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
+        if (!ispipe &&
+            do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file) != 0)
                 goto close_fail;
 
-        retval = binfmt->core_dump(signr, regs, file, core_limit);
+        retval = binfmt->core_dump(&cprm);
 
         if (retval)
                 current->signal->group_exit_code |= 0x80;
 close_fail:
         if (ispipe && core_pipe_limit)
-                wait_for_dump_helpers(file);
-        filp_close(file, NULL);
+                wait_for_dump_helpers(cprm.file);
+        filp_close(cprm.file, NULL);
 fail_dropcount:
         if (dump_count)
                 atomic_dec(&core_dump_count);