From 1f03d841b2872f5118fc7cbde39f0f19021d16ae Mon Sep 17 00:00:00 2001

From: Hector Marco-Gisbert <hecmargi@upv.es>

Date: Fri, 13 Nov 2015 16:21:09 +0100

Subject: [PATCH 137/198] Fix security issue when reading username and password

  This patch fixes two integer underflows at:

    * grub-core/lib/crypto.c

    * grub-core/normal/auth.c

Resolves: CVE-2015-8370

Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es>

Signed-off-by: Ismael Ripoll-Ripoll <iripoll@disca.upv.es>

---

 grub-core/lib/crypto.c  | 2 +-

 grub-core/normal/auth.c | 2 +-

 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/grub-core/lib/crypto.c b/grub-core/lib/crypto.c

index ca334d5a4..e6c78d16d 100644

--- a/grub-core/lib/crypto.c

+++ b/grub-core/lib/crypto.c

@@ -468,7 +468,7 @@ grub_password_get (char buf[], unsigned buf_size)

 	  break;

 	}

-      if (key == '\b')

+      if (key == '\b' && cur_len)

 	{

 	  if (cur_len)

 	    cur_len--;

diff --git a/grub-core/normal/auth.c b/grub-core/normal/auth.c

index 6be678c0d..c35ce9724 100644

--- a/grub-core/normal/auth.c

+++ b/grub-core/normal/auth.c

@@ -172,7 +172,7 @@ grub_username_get (char buf[], unsigned buf_size)

 	  break;

 	}

-      if (key == GRUB_TERM_BACKSPACE)

+      if (key == GRUB_TERM_BACKSPACE && cur_len)

 	{

 	  if (cur_len)

 	    {

-- 

2.14.3