From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Darren Kenny <darren.kenny@oracle.com>

Date: Thu, 26 Nov 2020 10:41:54 +0000

Subject: [PATCH] libgcrypt/mpi: Fix possible NULL dereference

The code in gcry_mpi_scan() assumes that buffer is not NULL, but there

is no explicit check for that, so we add one.

Fixes: CID 73757

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/lib/libgcrypt/mpi/mpicoder.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/grub-core/lib/libgcrypt/mpi/mpicoder.c b/grub-core/lib/libgcrypt/mpi/mpicoder.c

index 7ecad27b2..6fe389165 100644

--- a/grub-core/lib/libgcrypt/mpi/mpicoder.c

+++ b/grub-core/lib/libgcrypt/mpi/mpicoder.c

@@ -379,6 +379,9 @@ gcry_mpi_scan (struct gcry_mpi **ret_mpi, enum gcry_mpi_format format,

   unsigned int len;

   int secure = (buffer && gcry_is_secure (buffer));

+  if (!buffer)

+    return gcry_error (GPG_ERR_INV_ARG);

+

   if (format == GCRYMPI_FMT_SSH)

     len = 0;

   else