diff options
Diffstat (limited to 'debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-parsing-a-volume-label.patch')
-rw-r--r-- | debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-parsing-a-volume-label.patch | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-parsing-a-volume-label.patch b/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-parsing-a-volume-label.patch new file mode 100644 index 0000000..24601f7 --- /dev/null +++ b/debian/patches/ntfs-cve-fixes/fs-ntfs-Fix-an-OOB-read-when-parsing-a-volume-label.patch @@ -0,0 +1,57 @@ +From: Maxim Suhanov <dfirblog@gmail.com> +Date: Mon, 28 Aug 2023 16:38:19 +0300 +Subject: 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 bb70c89..ff5e374 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: |