From eb917d346bc8592924c5f6566b01841176c53c8c Mon Sep 17 00:00:00 2001

From: Tomas Bzatek <tbzatek@redhat.com>

Date: Mon, 22 Aug 2022 16:27:11 +0200

Subject: [PATCH] udiskslinuxblock: Only permit ATA Secure Erase during

 Format() on a whole block device

ATA Secure Erase requested as an option to the Format() method call used

to perform the actual erase on a whole drive object it looked up. When

Format() was called on a partition, this led to data loss on a whole drive.

This commit adds a safeguard to check that the Format() is requested

on a whole block device.

Severity of this issue was slightly lowered by a failure to submit

the ATA Secure erase command in case some filesystem was mounted

at that point.

---

 src/udiskslinuxblock.c | 16 ++++++++++++++++

 1 file changed, 16 insertions(+)

diff --git a/src/udiskslinuxblock.c b/src/udiskslinuxblock.c

index d1da94edf..db0ed2bf6 100644

--- a/src/udiskslinuxblock.c

+++ b/src/udiskslinuxblock.c

@@ -2354,6 +2354,7 @@ erase_ata_device (UDisksBlock   *block,

 {

   gboolean ret = FALSE;

   UDisksObject *drive_object = NULL;

+  UDisksLinuxBlockObject *block_object = NULL;

   UDisksDriveAta *ata = NULL;

   drive_object = udisks_daemon_find_object (daemon, udisks_block_get_drive (block));

@@ -2369,6 +2370,20 @@ erase_ata_device (UDisksBlock   *block,

       goto out;

     }

+  /* Reverse check to ensure we're erasing whole block device and not a partition */

+  block_object = udisks_linux_drive_object_get_block (UDISKS_LINUX_DRIVE_OBJECT (drive_object), FALSE /* get_hw */);

+  if (block_object == NULL)

+    {

+      g_set_error (error, UDISKS_ERROR, UDISKS_ERROR_FAILED, "Couldn't find a block device for the drive to erase");

+      goto out;

+    }

+  if (g_strcmp0 (g_dbus_object_get_object_path (G_DBUS_OBJECT (object)),

+                 g_dbus_object_get_object_path (G_DBUS_OBJECT (block_object))) != 0)

+    {

+      g_set_error (error, UDISKS_ERROR, UDISKS_ERROR_FAILED, "ATA secure erase needs to be performed on a whole block device");

+      goto out;

+    }

+

   /* sleep a tiny bit here to avoid the secure erase code racing with

    * programs spawned by udev

    */

@@ -2382,6 +2397,7 @@ erase_ata_device (UDisksBlock   *block,

  out:

   g_clear_object (&ata;;

   g_clear_object (&drive_object);

+  g_clear_object (&block_object);

   return ret;

 }