grub2/0015-video-readers-jpeg-Block-int-underflow-wild-pointer-.patch
Michael Chang e016790fe1 Accepting request 981228 from home:michael-chang:branches:Base:System
- Security fixes and hardenings for boothole 3 / boothole 2022 (bsc#1198581)
  * 0001-video-Remove-trailing-whitespaces.patch
  * 0002-loader-efi-chainloader-Simplify-the-loader-state.patch
  * 0003-commands-boot-Add-API-to-pass-context-to-loader.patch
- Fix CVE-2022-28736 (bsc#1198496)
  * 0004-loader-efi-chainloader-Use-grub_loader_set_ex.patch
- Fix CVE-2022-28735 (bsc#1198495)
  * 0005-kern-efi-sb-Reject-non-kernel-files-in-the-shim_lock.patch
  * 0006-kern-file-Do-not-leak-device_name-on-error-in-grub_f.patch
  * 0007-video-readers-png-Abort-sooner-if-a-read-operation-f.patch
  * 0008-video-readers-png-Refuse-to-handle-multiple-image-he.patch
- Fix CVE-2021-3695 (bsc#1191184)
  * 0009-video-readers-png-Drop-greyscale-support-to-fix-heap.patch
- Fix CVE-2021-3696 (bsc#1191185)
  * 0010-video-readers-png-Avoid-heap-OOB-R-W-inserting-huff-.patch
  * 0011-video-readers-png-Sanity-check-some-huffman-codes.patch
  * 0012-video-readers-jpeg-Abort-sooner-if-a-read-operation-.patch
  * 0013-video-readers-jpeg-Do-not-reallocate-a-given-huff-ta.patch
  * 0014-video-readers-jpeg-Refuse-to-handle-multiple-start-o.patch
- Fix CVE-2021-3697 (bsc#1191186)
  * 0015-video-readers-jpeg-Block-int-underflow-wild-pointer-.patch
  * 0016-normal-charset-Fix-array-out-of-bounds-formatting-un.patch
- Fix CVE-2022-28733 (bsc#1198460)
  * 0017-net-ip-Do-IP-fragment-maths-safely.patch
  * 0018-net-netbuff-Block-overly-large-netbuff-allocs.patch
  * 0019-net-dns-Fix-double-free-addresses-on-corrupt-DNS-res.patch
  * 0020-net-dns-Don-t-read-past-the-end-of-the-string-we-re-.patch
  * 0021-net-tftp-Prevent-a-UAF-and-double-free-from-a-failed.patch
  * 0022-net-tftp-Avoid-a-trivial-UAF.patch
  * 0023-net-http-Do-not-tear-down-socket-if-it-s-already-bee.patch

OBS-URL: https://build.opensuse.org/request/show/981228
OBS-URL: https://build.opensuse.org/package/show/Base:System/grub2?expand=0&rev=416
2022-06-08 03:04:17 +00:00

78 lines
2.5 KiB
Diff

From 9a6e9ad21eb2f414dce6eaedd41e146a28142101 Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@axtens.net>
Date: Wed, 7 Jul 2021 15:38:19 +1000
Subject: [PATCH 15/32] video/readers/jpeg: Block int underflow -> wild pointer
write
Certain 1 px wide images caused a wild pointer write in
grub_jpeg_ycrcb_to_rgb(). This was caused because in grub_jpeg_decode_data(),
we have the following loop:
for (; data->r1 < nr1 && (!data->dri || rst);
data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3)
We did not check if vb * width >= hb * nc1.
On a 64-bit platform, if that turns out to be negative, it will underflow,
be interpreted as unsigned 64-bit, then be added to the 64-bit pointer, so
we see data->bitmap_ptr jump, e.g.:
0x6180_0000_0480 to
0x6181_0000_0498
^
~--- carry has occurred and this pointer is now far away from
any object.
On a 32-bit platform, it will decrement the pointer, creating a pointer
that won't crash but will overwrite random data.
Catch the underflow and error out.
Fixes: CVE-2021-3697
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/video/readers/jpeg.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
index 1df1171d78..97a533b24f 100644
--- a/grub-core/video/readers/jpeg.c
+++ b/grub-core/video/readers/jpeg.c
@@ -23,6 +23,7 @@
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/bufio.h>
+#include <grub/safemath.h>
GRUB_MOD_LICENSE ("GPLv3+");
@@ -693,6 +694,7 @@ static grub_err_t
grub_jpeg_decode_data (struct grub_jpeg_data *data)
{
unsigned c1, vb, hb, nr1, nc1;
+ unsigned stride_a, stride_b, stride;
int rst = data->dri;
grub_err_t err = GRUB_ERR_NONE;
@@ -705,8 +707,14 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data)
return grub_error (GRUB_ERR_BAD_FILE_TYPE,
"jpeg: attempted to decode data before start of stream");
+ if (grub_mul(vb, data->image_width, &stride_a) ||
+ grub_mul(hb, nc1, &stride_b) ||
+ grub_sub(stride_a, stride_b, &stride))
+ return grub_error (GRUB_ERR_BAD_FILE_TYPE,
+ "jpeg: cannot decode image with these dimensions");
+
for (; data->r1 < nr1 && (!data->dri || rst);
- data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3)
+ data->r1++, data->bitmap_ptr += stride * 3)
for (c1 = 0; c1 < nc1 && (!data->dri || rst);
c1++, rst--, data->bitmap_ptr += hb * 3)
{
--
2.34.1