From: Xiangyu Chen
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.
Signed-off-by: Xiangyu Chen
Signed-off-by: Steve Sakoman
---
.../grub/files/CVE-2023-4693.patch| 63 +++
meta/recipes-bsp/grub/grub2.inc | 1 +
2 files changed, 64 insertions(+)
create mode 100644 meta/recipes-bsp/grub/files/CVE-2023-4693.patch
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 00..544226a9aa
--- /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
+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
+Signed-off-by: Maxim Suhanov
+Reviewed-by: Daniel Kiper
+Signed-off-by: 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 ac73a0b940..fa949fc081 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -43,6 +43,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
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"
--
2.34.1
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