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From eb917d346bc8592924c5f6566b01841176c53c8c Mon Sep 17 00:00:00 2001
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From: Tomas Bzatek <tbzatek@redhat.com>
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Date: Mon, 22 Aug 2022 16:27:11 +0200
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Subject: [PATCH] udiskslinuxblock: Only permit ATA Secure Erase during
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 Format() on a whole block device
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ATA Secure Erase requested as an option to the Format() method call used
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to perform the actual erase on a whole drive object it looked up. When
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Format() was called on a partition, this led to data loss on a whole drive.
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This commit adds a safeguard to check that the Format() is requested
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on a whole block device.
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Severity of this issue was slightly lowered by a failure to submit
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the ATA Secure erase command in case some filesystem was mounted
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at that point.
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---
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 src/udiskslinuxblock.c | 16 ++++++++++++++++
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 1 file changed, 16 insertions(+)
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diff --git a/src/udiskslinuxblock.c b/src/udiskslinuxblock.c
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index d1da94edf..db0ed2bf6 100644
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--- a/src/udiskslinuxblock.c
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+++ b/src/udiskslinuxblock.c
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@@ -2354,6 +2354,7 @@ erase_ata_device (UDisksBlock   *block,
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 {
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   gboolean ret = FALSE;
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   UDisksObject *drive_object = NULL;
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+  UDisksLinuxBlockObject *block_object = NULL;
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   UDisksDriveAta *ata = NULL;
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   drive_object = udisks_daemon_find_object (daemon, udisks_block_get_drive (block));
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@@ -2369,6 +2370,20 @@ erase_ata_device (UDisksBlock   *block,
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       goto out;
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     }
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+  /* Reverse check to ensure we're erasing whole block device and not a partition */
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+  block_object = udisks_linux_drive_object_get_block (UDISKS_LINUX_DRIVE_OBJECT (drive_object), FALSE /* get_hw */);
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+  if (block_object == NULL)
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+    {
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+      g_set_error (error, UDISKS_ERROR, UDISKS_ERROR_FAILED, "Couldn't find a block device for the drive to erase");
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+      goto out;
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+    }
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+  if (g_strcmp0 (g_dbus_object_get_object_path (G_DBUS_OBJECT (object)),
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+                 g_dbus_object_get_object_path (G_DBUS_OBJECT (block_object))) != 0)
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+    {
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+      g_set_error (error, UDISKS_ERROR, UDISKS_ERROR_FAILED, "ATA secure erase needs to be performed on a whole block device");
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+      goto out;
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+    }
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+
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   /* sleep a tiny bit here to avoid the secure erase code racing with
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    * programs spawned by udev
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    */
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@@ -2382,6 +2397,7 @@ erase_ata_device (UDisksBlock   *block,
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  out:
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   g_clear_object (&ata;;
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   g_clear_object (&drive_object);
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+  g_clear_object (&block_object);
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   return ret;
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 }
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