grub: Fix for CVE-2023-4692 and CVE-2023-4693

CVE: CVE-2023-4692

Crafted file system images can cause heap-based buffer
overflow and may allow arbitrary code execution and secure boot bypass.

Upstream-Status: Backport
[https://git.savannah.gnu.org/cgit/grub.git/commit/?id=43651027d24e62a7a463254165e1e46e42aecdea]

CVE: CVE-2023-4693

There an out-of-bounds read at fs/ntfs.c, a physically present attacker
may leverage that by presenting a specially crafted NTFS file system
image to read arbitrary memory locations. A successful attack may allow
sensitive data cached in memory or EFI variables values to be leaked
presenting a high Confidentiality risk.

Upstream-Status: Backport
[https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0ed2458cc4eff6d9a9199527e2a0b6d445802f94]

(From OE-Core rev: a8bc6f041599ce8da275c163c87f155a2f09369c)

Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 163 insertions, 0 deletions

diff --git a/meta/recipes-bsp/grub/files/CVE-2023-4692.patch b/meta/recipes-bsp/grub/files/CVE-2023-4692.patch
new file mode 100644
index 0000000000..305fcc93d8
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/CVE-2023-4692.patch
@@ -0,0 +1,98 @@
+From 43651027d24e62a7a463254165e1e46e42aecdea Mon Sep 17 00:00:00 2001
+From: Maxim Suhanov <dfirblog@gmail.com>
+Date: Mon, 28 Aug 2023 16:31:57 +0300
+Subject: [PATCH] fs/ntfs: Fix an OOB write when parsing the $ATTRIBUTE_LIST attribute
+ for the $MFT file
+
+When parsing an extremely fragmented $MFT file, i.e., the file described
+using the $ATTRIBUTE_LIST attribute, current NTFS code will reuse a buffer
+containing bytes read from the underlying drive to store sector numbers,
+which are consumed later to read data from these sectors into another buffer.
+
+These sectors numbers, two 32-bit integers, are always stored at predefined
+offsets, 0x10 and 0x14, relative to first byte of the selected entry within
+the $ATTRIBUTE_LIST attribute. Usually, this won't cause any problem.
+
+However, when parsing a specially-crafted file system image, this may cause
+the NTFS code to write these integers beyond the buffer boundary, likely
+causing the GRUB memory allocator to misbehave or fail. These integers contain
+values which are controlled by on-disk structures of the NTFS file system.
+
+Such modification and resulting misbehavior may touch a memory range not
+assigned to the GRUB and owned by firmware or another EFI application/driver.
+
+This fix introduces checks to ensure that these sector numbers are never
+written beyond the boundary.
+
+Fixes: CVE-2023-4692
+
+Upstream-Status: Backport from 
+[https://git.savannah.gnu.org/cgit/grub.git/commit/?id=43651027d24e62a7a463254165e1e46e42aecdea]
+CVE: CVE-2023-4692
+
+Reported-by: Maxim Suhanov <dfirblog@gmail.com>
+Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
+---
+ grub-core/fs/ntfs.c | 18 +++++++++++++++++-
+ 1 file changed, 17 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
+index bbdbe24..c3c4db1 100644
+--- a/grub-core/fs/ntfs.c
++++ b/grub-core/fs/ntfs.c
+@@ -184,7 +184,7 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+     }
+   if (at->attr_end)
+     {
+-      grub_uint8_t *pa;
++      grub_uint8_t *pa, *pa_end;
+ 
+       at->emft_buf = grub_malloc (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR);
+       if (at->emft_buf == NULL)
+@@ -209,11 +209,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+            }
+          at->attr_nxt = at->edat_buf;
+          at->attr_end = at->edat_buf + u32at (pa, 0x30);
++         pa_end = at->edat_buf + n;
+        }
+       else
+        {
+          at->attr_nxt = at->attr_end + u16at (pa, 0x14);
+          at->attr_end = at->attr_end + u32at (pa, 4);
++         pa_end = at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR);
+        }
+       at->flags |= GRUB_NTFS_AF_ALST;
+       while (at->attr_nxt < at->attr_end)
+@@ -230,6 +232,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+          at->flags |= GRUB_NTFS_AF_GPOS;
+          at->attr_cur = at->attr_nxt;
+          pa = at->attr_cur;
++
++         if ((pa >= pa_end) || (pa_end - pa < 0x18))
++           {
++             grub_error (GRUB_ERR_BAD_FS, "can\'t parse attribute list");
++             return NULL;
++           }
++
+          grub_set_unaligned32 ((char *) pa + 0x10,
+                                grub_cpu_to_le32 (at->mft->data->mft_start));
+          grub_set_unaligned32 ((char *) pa + 0x14,
+@@ -240,6 +249,13 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+            {
+              if (*pa != attr)
+                break;
++
++              if ((pa >= pa_end) || (pa_end - pa < 0x18))
++                {
++                 grub_error (GRUB_ERR_BAD_FS, "can\'t parse attribute list");
++                 return NULL;
++               }
++
+              if (read_attr
+                  (at, pa + 0x10,
+                   u32at (pa, 0x10) * (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR),
+-- 
+cgit v1.1
+
diff --git a/meta/recipes-bsp/grub/files/CVE-2023-4693.patch b/meta/recipes-bsp/grub/files/CVE-2023-4693.patch
new file mode 100644
index 0000000000..420fe92ac3
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/CVE-2023-4693.patch
@@ -0,0 +1,63 @@
+From 0ed2458cc4eff6d9a9199527e2a0b6d445802f94 Mon Sep 17 00:00:00 2001
+From: Maxim Suhanov <dfirblog@...>
+Date: Mon, 28 Aug 2023 16:32:33 +0300
+Subject: fs/ntfs: Fix an OOB read when reading data from the resident $DATA
+ attribute
+
+When reading a file containing resident data, i.e., the file data is stored in
+the $DATA attribute within the NTFS file record, not in external clusters,
+there are no checks that this resident data actually fits the corresponding
+file record segment.
+
+When parsing a specially-crafted file system image, the current NTFS code will
+read the file data from an arbitrary, attacker-chosen memory offset and of
+arbitrary, attacker-chosen length.
+
+This allows an attacker to display arbitrary chunks of memory, which could
+contain sensitive information like password hashes or even plain-text,
+obfuscated passwords from BS EFI variables.
+
+This fix implements a check to ensure that resident data is read from the
+corresponding file record segment only.
+
+Fixes: CVE-2023-4693
+
+Upstream-Status: Backport from 
+[https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0ed2458cc4eff6d9a9199527e2a0b6d445802f94]
+CVE: CVE-2023-4693
+
+Reported-by: Maxim Suhanov <dfirblog@...>
+Signed-off-by: Maxim Suhanov <dfirblog@...>
+Reviewed-by: Daniel Kiper <daniel.kiper@...>
+Signed-off-by: Xiangyu Chen <xiangyu.chen@...>
+---
+ grub-core/fs/ntfs.c | 13 ++++++++++++-
+ 1 file changed, 12 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
+index c3c4db1..a68e173 100644
+--- a/grub-core/fs/ntfs.c
++++ b/grub-core/fs/ntfs.c
+@@ -401,7 +401,18 @@ read_data (struct grub_ntfs_attr *at, grub_uint8_t *pa, grub_uint8_t *dest,
+     {
+       if (ofs + len > u32at (pa, 0x10))
+        return grub_error (GRUB_ERR_BAD_FS, "read out of range");
+-      grub_memcpy (dest, pa + u32at (pa, 0x14) + ofs, len);
++
++      if (u32at (pa, 0x10) > (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
++       return grub_error (GRUB_ERR_BAD_FS, "resident attribute too large");
++
++      if (pa >= at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
++       return grub_error (GRUB_ERR_BAD_FS, "resident attribute out of range");
++
++      if (u16at (pa, 0x14) + u32at (pa, 0x10) >
++         (grub_addr_t) at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR) - (grub_addr_t) pa)
++       return grub_error (GRUB_ERR_BAD_FS, "resident attribute out of range");
++
++      grub_memcpy (dest, pa + u16at (pa, 0x14) + ofs, len);
+       return 0;
+     }
+ 
+-- 
+cgit v1.1
+
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index 41839698dc..f594e7d3a4 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -42,6 +42,8 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
            file://CVE-2022-3775.patch \
            file://0001-risc-v-Handle-R_RISCV_CALL_PLT-reloc.patch \
            file://0001-fs-ext2-Ignore-checksum-seed-incompat-feature.patch \
+           file://CVE-2023-4692.patch \
+           file://CVE-2023-4693.patch \
 "
 
 SRC_URI[sha256sum] = "23b64b4c741569f9426ed2e3d0e6780796fca081bee4c99f62aa3f53ae803f5f"