« Previous | Next » 

Revision 319ae529

ID319ae529b8d55ea60b1036809aaab2130048d0e1

Added by Markus Armbruster over 13 years ago

blockdev: Fix drive_add for drives without media

Watch this:

(qemu) drive_add 0 if=none
    (qemu) info block
    none0: type=hd removable=0 [not inserted]
    (qemu) drive_del none0
    Segmentation fault (core dumped)

add_init_drive() is confused about drive_init()'s failure modes, and
cleans up when it shouldn't. This leaves the DriveInfo with member
opts dangling. drive_del attempts to free it, and dies.

drive_init() behaves as follows:

  • If it created a drive with media, it returns its DriveInfo.
  • If it created a drive without media, it clears *fatal_error and
    returns NULL.
  • If it couldn't create a drive, it sets *fatal_error and returns
    NULL.

Of its three callers:

  • drive_init_func() is correct.
  • usb_msd_init() assumes drive_init() failed when it returns NULL.
    This is correct only because it always passes option "file", and
    "drive without media" can't happen then.
  • add_init_drive() assumes drive_init() failed when it returns NULL.
    This is incorrect.

Clean up drive_init() to return NULL on failure and only on failure.
Drop its parameter fatal_error.

Signed-off-by: Markus Armbruster <>
Signed-off-by: Kevin Wolf <>

Files

  • added
  • modified
  • copied
  • renamed
  • deleted

View differences