You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
62 lines
2.0 KiB
62 lines
2.0 KiB
3 months ago
|
From 1fe82c41e070385e273d7bb1cfb482627a3c28e8 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Maxim Suhanov <dfirblog@gmail.com>
|
||
|
|
Date: Mon, 28 Aug 2023 16:38:19 +0300
|
||
|
|
Subject: [PATCH 5/6] fs/ntfs: Fix an OOB read when parsing a volume label
|
||
|
|
|
||
|
|
This fix introduces checks to ensure that an NTFS volume label is always
|
||
|
|
read from the corresponding file record segment.
|
||
|
|
|
||
|
|
The current NTFS code allows the volume label string to be read from an
|
||
|
|
arbitrary, attacker-chosen memory location. However, the bytes read are
|
||
|
|
always treated as UTF-16LE. So, the final string displayed is mostly
|
||
|
|
unreadable and it can't be easily converted back to raw bytes.
|
||
|
|
|
||
|
|
The lack of this check is a minor issue, likely not causing a significant
|
||
|
|
data leak.
|
||
|
|
|
||
|
|
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 | 18 +++++++++++++++++-
|
||
|
|
1 file changed, 17 insertions(+), 1 deletion(-)
|
||
|
|
|
||
|
|
diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
|
||
|
|
index bb70c89fb803..ff5e3740f0dd 100644
|
||
|
|
--- a/grub-core/fs/ntfs.c
|
||
|
|
+++ b/grub-core/fs/ntfs.c
|
||
|
|
@@ -1213,13 +1213,29 @@ grub_ntfs_label (grub_device_t device, char **label)
|
||
|
|
|
||
|
|
init_attr (&mft->attr, mft);
|
||
|
|
pa = find_attr (&mft->attr, GRUB_NTFS_AT_VOLUME_NAME);
|
||
|
|
+
|
||
|
|
+ if (pa >= mft->buf + (mft->data->mft_size << GRUB_NTFS_BLK_SHR))
|
||
|
|
+ {
|
||
|
|
+ grub_error (GRUB_ERR_BAD_FS, "can\'t parse volume label");
|
||
|
|
+ goto fail;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
+ if (mft->buf + (mft->data->mft_size << GRUB_NTFS_BLK_SHR) - pa < 0x16)
|
||
|
|
+ {
|
||
|
|
+ grub_error (GRUB_ERR_BAD_FS, "can\'t parse volume label");
|
||
|
|
+ goto fail;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
if ((pa) && (pa[8] == 0) && (u32at (pa, 0x10)))
|
||
|
|
{
|
||
|
|
int len;
|
||
|
|
|
||
|
|
len = u32at (pa, 0x10) / 2;
|
||
|
|
pa += u16at (pa, 0x14);
|
||
|
|
- *label = get_utf8 (pa, len);
|
||
|
|
+ if (mft->buf + (mft->data->mft_size << GRUB_NTFS_BLK_SHR) - pa >= 2 * len)
|
||
|
|
+ *label = get_utf8 (pa, len);
|
||
|
|
+ else
|
||
|
|
+ grub_error (GRUB_ERR_BAD_FS, "can\'t parse volume label");
|
||
|
|
}
|
||
|
|
|
||
|
|
fail:
|
||
|
|
--
|
||
|
|
2.43.0
|
||
|
|
|