1 files changed, 67 insertions, 12 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 7761837e4500..6d2b6f936858 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -361,13 +361,13 @@ err:
 /*
  * count() counts the number of strings in array ARGV.
  */
-static int count(char __user * __user * argv, int max)
+static int count(const char __user * const __user * argv, int max)
 {
         int i = 0;
 
         if (argv != NULL) {
                 for (;;) {
-                        char __user * p;
+                        const char __user * p;
 
                         if (get_user(p, argv))
                                 return -EFAULT;
@@ -376,6 +376,9 @@ static int count(char __user * __user * argv, int max)
                         argv++;
                         if (i++ >= max)
                                 return -E2BIG;
+
+                        if (fatal_signal_pending(current))
+                                return -ERESTARTNOHAND;
                         cond_resched();
                 }
         }
@@ -387,7 +390,7 @@ static int count(char __user * __user * argv, int max)
  * processes's memory to the new process's stack.  The call to get_user_pages()
  * ensures the destination page is created and not swapped out.
  */
-static int copy_strings(int argc, char __user * __user * argv,
+static int copy_strings(int argc, const char __user *const __user *argv,
                         struct linux_binprm *bprm)
 {
         struct page *kmapped_page = NULL;
@@ -396,7 +399,7 @@ static int copy_strings(int argc, char __user * __user * argv,
         int ret;
 
         while (argc-- > 0) {
-                char __user *str;
+                const char __user *str;
                 int len;
                 unsigned long pos;
 
@@ -419,6 +422,12 @@ static int copy_strings(int argc, char __user * __user * argv,
                 while (len > 0) {
                         int offset, bytes_to_copy;
 
+                        if (fatal_signal_pending(current)) {
+                                ret = -ERESTARTNOHAND;
+                                goto out;
+                        }
+                        cond_resched();
+
                         offset = pos % PAGE_SIZE;
                         if (offset == 0)
                                 offset = PAGE_SIZE;
@@ -470,12 +479,13 @@ out:
 /*
  * Like copy_strings, but get argv and its values from kernel memory.
  */
-int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
+int copy_strings_kernel(int argc, const char *const *argv,
+                        struct linux_binprm *bprm)
 {
         int r;
         mm_segment_t oldfs = get_fs();
         set_fs(KERNEL_DS);
-        r = copy_strings(argc, (char __user * __user *)argv, bprm);
+        r = copy_strings(argc, (const char __user *const  __user *)argv, bprm);
         set_fs(oldfs);
         return r;
 }
@@ -593,6 +603,11 @@ int setup_arg_pages(struct linux_binprm *bprm,
 #else
         stack_top = arch_align_stack(stack_top);
         stack_top = PAGE_ALIGN(stack_top);
+
+        if (unlikely(stack_top < mmap_min_addr) ||
+            unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
+                return -ENOMEM;
+
         stack_shift = vma->vm_end - stack_top;
 
         bprm->p -= stack_shift;
@@ -997,7 +1012,7 @@ EXPORT_SYMBOL(flush_old_exec);
 void setup_new_exec(struct linux_binprm * bprm)
 {
         int i, ch;
-        char * name;
+        const char *name;
         char tcomm[sizeof(current->comm)];
 
         arch_pick_mmap_layout(current->mm);
@@ -1117,7 +1132,7 @@ int check_unsafe_exec(struct linux_binprm *bprm)
         bprm->unsafe = tracehook_unsafe_exec(p);
 
         n_fs = 1;
-        write_lock(&p->fs->lock);
+        spin_lock(&p->fs->lock);
         rcu_read_lock();
         for (t = next_thread(p); t != p; t = next_thread(t)) {
                 if (t->fs == p->fs)
@@ -1134,7 +1149,7 @@ int check_unsafe_exec(struct linux_binprm *bprm)
                         res = 1;
                 }
         }
-        write_unlock(&p->fs->lock);
+        spin_unlock(&p->fs->lock);
 
         return res;
 }
@@ -1316,9 +1331,9 @@ EXPORT_SYMBOL(search_binary_handler);
 /*
  * sys_execve() executes a new program.
  */
-int do_execve(char * filename,
-        char __user *__user *argv,
-        char __user *__user *envp,
+int do_execve(const char * filename,
+        const char __user *const __user *argv,
+        const char __user *const __user *envp,
         struct pt_regs * regs)
 {
         struct linux_binprm *bprm;
@@ -1999,3 +2014,43 @@ fail_creds:
 fail:
         return;
 }
+
+/*
+ * Core dumping helper functions.  These are the only things you should
+ * do on a core-file: use only these functions to write out all the
+ * necessary info.
+ */
+int dump_write(struct file *file, const void *addr, int nr)
+{
+        return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+}
+EXPORT_SYMBOL(dump_write);
+
+int dump_seek(struct file *file, loff_t off)
+{
+        int ret = 1;
+
+        if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
+                if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+                        return 0;
+        } else {
+                char *buf = (char *)get_zeroed_page(GFP_KERNEL);
+
+                if (!buf)
+                        return 0;
+                while (off > 0) {
+                        unsigned long n = off;
+
+                        if (n > PAGE_SIZE)
+                                n = PAGE_SIZE;
+                        if (!dump_write(file, buf, n)) {
+                                ret = 0;
+                                break;
+                        }
+                        off -= n;
+                }
+                free_page((unsigned long)buf);
+        }
+        return ret;
+}
+EXPORT_SYMBOL(dump_seek);