grub2/0338-fs-ntfs-Fix-an-OOB-read-when-parsing-bitmaps-for-ind.patch
Nicolas Frayer 50a93da15d fs/ntfs: OOB write fix
(CVE-2023-4692)

Resolves: #RHEL-11567
Signed-off-by: Nicolas Frayer <nfrayer@redhat.com>
2024-02-20 12:40:47 +01:00

52 lines
1.6 KiB
Diff

From 7a5a116739fa6d8a625da7d6b9272c9a2462f967 Mon Sep 17 00:00:00 2001
From: Maxim Suhanov <dfirblog@gmail.com>
Date: Mon, 28 Aug 2023 16:33:44 +0300
Subject: [PATCH 4/6] fs/ntfs: Fix an OOB read when parsing bitmaps for index
attributes
This fix introduces checks to ensure that bitmaps for directory indices
are never read beyond their actual sizes.
The lack of this check is a minor issue, likely not exploitable in any way.
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 | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
index 2d78b96e19fb..bb70c89fb803 100644
--- a/grub-core/fs/ntfs.c
+++ b/grub-core/fs/ntfs.c
@@ -843,6 +843,25 @@ grub_ntfs_iterate_dir (grub_fshelp_node_t dir,
if (is_resident)
{
+ if (bitmap_len > (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
+ {
+ grub_error (GRUB_ERR_BAD_FS, "resident bitmap too large");
+ goto done;
+ }
+
+ if (cur_pos >= at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
+ {
+ grub_error (GRUB_ERR_BAD_FS, "resident bitmap out of range");
+ goto done;
+ }
+
+ if (u16at (cur_pos, 0x14) + u32at (cur_pos, 0x10) >
+ (grub_addr_t) at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR) - (grub_addr_t) cur_pos)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "resident bitmap out of range");
+ goto done;
+ }
+
grub_memcpy (bmp, cur_pos + u16at (cur_pos, 0x14),
bitmap_len);
}
--
2.43.0