kumquat-buildroot/boot/grub2/0013-net-ip-Do-IP-fragment-maths-safely.patch
Thomas Petazzoni 65c99394ff boot/grub2: backport fixes for numerous CVEs
Grub 2.06 is affected by a number of CVEs, which have been fixed in
the master branch of Grub, but are not yet part of any release (there
is a 2.12-rc1 release, but nothing else between 2.06 and 2.12-rc1).

So this patch backports the relevant fixes for CVE-2022-28736,
CVE-2022-28735, CVE-2021-3695, CVE-2021-3696, CVE-2021-3697,
CVE-2022-28733, CVE-2022-28734, CVE-2022-2601 and CVE-2022-3775.

It should be noted that CVE-2021-3695, CVE-2021-3696, CVE-2021-3697
are not reported as affecting Grub by our CVE matching logic because
the NVD database uses an incorrect CPE ID in those CVEs: it uses
"grub" as the product instead of "grub2" like all other CVEs for
grub. This issue has been reported to the NVD maintainers.

This requires backporting a lot of patches, but jumping from 2.06 to
2.12-rc1 implies getting 592 commits, which is quite a lot.

All Grub test cases are working fine:

  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/984500585
  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/984500679

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[Arnout: fix check-package warning in patch 0002]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
2023-08-30 21:54:23 +02:00

57 lines
1.8 KiB
Diff

From cadde7e36b8797060ac8cdf7cca7d8e1e09697e6 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Mon, 20 Dec 2021 19:41:21 +1100
Subject: [PATCH] net/ip: Do IP fragment maths safely
We can receive packets with invalid IP fragmentation information. This
can lead to rsm->total_len underflowing and becoming very large.
Then, in grub_netbuff_alloc(), we add to this very large number, which can
cause it to overflow and wrap back around to a small positive number.
The allocation then succeeds, but the resulting buffer is too small and
subsequent operations can write past the end of the buffer.
Catch the underflow here.
Fixes: CVE-2022-28733
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream: 3e4817538de828319ba6d59ced2fbb9b5ca13287
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
grub-core/net/ip.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/grub-core/net/ip.c b/grub-core/net/ip.c
index ea5edf8f1..74e4e8b06 100644
--- a/grub-core/net/ip.c
+++ b/grub-core/net/ip.c
@@ -25,6 +25,7 @@
#include <grub/net/netbuff.h>
#include <grub/mm.h>
#include <grub/priority_queue.h>
+#include <grub/safemath.h>
#include <grub/time.h>
struct iphdr {
@@ -512,7 +513,14 @@ grub_net_recv_ip4_packets (struct grub_net_buff *nb,
{
rsm->total_len = (8 * (grub_be_to_cpu16 (iph->frags) & OFFSET_MASK)
+ (nb->tail - nb->data));
- rsm->total_len -= ((iph->verhdrlen & 0xf) * sizeof (grub_uint32_t));
+
+ if (grub_sub (rsm->total_len, (iph->verhdrlen & 0xf) * sizeof (grub_uint32_t),
+ &rsm->total_len))
+ {
+ grub_dprintf ("net", "IP reassembly size underflow\n");
+ return GRUB_ERR_NONE;
+ }
+
rsm->asm_netbuff = grub_netbuff_alloc (rsm->total_len);
if (!rsm->asm_netbuff)
{
--
2.41.0