grub2/0356-fs-ntfs-Fix-an-OOB-read-when-parsing-bitmaps-for-ind.patch
Nicolas Frayer 4b81c6f969 GRUB2 NTFS driver vulnerabilities
(CVE-2023-4692)
(CVE-2023-4693)

Resolves: #2236613
Resolves: #2241978
Resolves: #2241976
Resolves: #2238343
Signed-off-by: Nicolas Frayer <nfrayer@redhat.com>
2024-03-12 14:57:26 +01:00

48 lines
1.6 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Maxim Suhanov <dfirblog@gmail.com>
Date: Tue, 3 Oct 2023 19:12:26 +0200
Subject: [PATCH] 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 72302033281a..74515114287f 100644
--- a/grub-core/fs/ntfs.c
+++ b/grub-core/fs/ntfs.c
@@ -839,6 +839,25 @@ 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);
}