1 files changed, 54 insertions, 0 deletions
diff --git a/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-reading-data-from-the-reside.patch b/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-reading-data-from-the-reside.patch
new file mode 100644
index 0000000..d762c06
--- /dev/null
+++ b/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-reading-data-from-the-reside.patch
@@ -0,0 +1,54 @@
+From: Maxim Suhanov <dfirblog@gmail.com>
+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
+
+Reported-by: Maxim Suhanov <dfirblog@gmail.com>
+Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ 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;
+     }
+