do_coredump(): check return from argv_split()

do_coredump() accesses helper_argv[0] without checking helper_argv !=
NULL.  This can happen if page allocation failed.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 6ca4e3d22a3d..6b09d6fa4f7e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1770,6 +1770,11 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
 
         if (ispipe) {
                 helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
+                if (!helper_argv) {
+                        printk(KERN_WARNING "%s failed to allocate memory\n",
+                               __func__);
+                        goto fail_unlock;
+                }
                 /* Terminate the string before the first option */
                 delimit = strchr(corename, ' ');
                 if (delimit)