grub2/SOURCES/0452-io-gzio-Zero-gzio-tl-t...

39 lines
1.3 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Thu, 21 Jan 2021 12:22:28 +1100
Subject: [PATCH] io/gzio: Zero gzio->tl/td in init_dynamic_block() if
huft_build() fails
If huft_build() fails, gzio->tl or gzio->td could contain pointers that
are no longer valid. Zero them out.
This prevents a double free when grub_gzio_close() comes through and
attempts to free them again.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/io/gzio.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/grub-core/io/gzio.c b/grub-core/io/gzio.c
index f85dbae23..e9f332fbc 100644
--- a/grub-core/io/gzio.c
+++ b/grub-core/io/gzio.c
@@ -1010,6 +1010,7 @@ init_dynamic_block (grub_gzio_t gzio)
gzio->bl = lbits;
if (huft_build (ll, nl, 257, cplens, cplext, &gzio->tl, &gzio->bl) != 0)
{
+ gzio->tl = 0;
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
"failed in building a Huffman code table");
return;
@@ -1019,6 +1020,7 @@ init_dynamic_block (grub_gzio_t gzio)
{
huft_free (gzio->tl);
gzio->tl = 0;
+ gzio->td = 0;
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
"failed in building a Huffman code table");
return;