grub2/0122-AUDIT-0-http-boot-tracker-bug.patch
Javier Martinez Canillas 7e98da058f
Cleanup our patchset to reduce the number of patches
This change reorganizes and cleanups our patches to reduce the patch number
from 314 patches to 187. That's achieved by dropping patches that are later
reverted and squashing fixes for earlier patches that introduced features.

There are no code changes and the diff with upstream is the same before and
after the cleanup. Having fewer patches makes easier to manage the patchset
and also will ease to rebase them on top of the latest grub-2.04 release.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
2019-07-16 12:30:06 +02:00

62 lines
2 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Sebastian Krahmer <krahmer@suse.com>
Date: Tue, 28 Nov 2017 17:24:38 +0800
Subject: [PATCH] AUDIT-0: http boot tracker bug
Fixing a memory leak in case of error, and a integer overflow, leading to a
heap overflow due to overly large chunk sizes.
We need to check against some maximum value, otherwise values like 0xffffffff
will eventually lead in the allocation functions to small sized buffers, since
the len is rounded up to the next reasonable alignment. The following memcpy
will then smash the heap, leading to RCE.
This is no big issue for pure http boot, since its going to execute an
untrusted kernel anyway, but it will break trusted boot scenarios, where only
signed code is allowed to be executed.
Signed-off-by: Michael Chang <mchang@suse.com>
---
grub-core/net/efi/net.c | 4 +++-
grub-core/net/http.c | 5 ++++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/grub-core/net/efi/net.c b/grub-core/net/efi/net.c
index 9e0078ac1c6..2bf15447fd5 100644
--- a/grub-core/net/efi/net.c
+++ b/grub-core/net/efi/net.c
@@ -645,8 +645,10 @@ grub_efihttp_chunk_read (grub_file_t file, char *buf,
rd = efi_net_interface (read, file, chunk, sz);
- if (rd <= 0)
+ if (rd <= 0) {
+ grub_free (chunk);
return rd;
+ }
if (buf)
{
diff --git a/grub-core/net/http.c b/grub-core/net/http.c
index 00737c52750..c9c59690a98 100644
--- a/grub-core/net/http.c
+++ b/grub-core/net/http.c
@@ -31,7 +31,8 @@ GRUB_MOD_LICENSE ("GPLv3+");
enum
{
- HTTP_PORT = 80
+ HTTP_PORT = 80,
+ HTTP_MAX_CHUNK_SIZE = 0x80000000
};
@@ -78,6 +79,8 @@ parse_line (grub_file_t file, http_data_t data, char *ptr, grub_size_t len)
if (data->in_chunk_len == 2)
{
data->chunk_rem = grub_strtoul (ptr, 0, 16);
+ if (data->chunk_rem > HTTP_MAX_CHUNK_SIZE)
+ return GRUB_ERR_NET_PACKET_TOO_BIG;
grub_errno = GRUB_ERR_NONE;
if (data->chunk_rem == 0)
{