It was possible to delete a loopback while there were still references
to it. This led to an exploitable use-after-free.
Fixed by implementing a reference counting in the grub_loopback struct.
Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A new option is added to the loopback command, -D or --decompress, which
when specified transparently decompresses the backing file. This allows
compressed images to be used as if they were uncompressed.
Add documentation to support this change.
Suggested-by: Li Gen <ligenlive@gmail.com>
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
If there is a loopback device with the same name as the one to be created,
instead of closing the old one and replacing it with the new one, return an
error instead. If the loopback device was created, its probably being used
by something and just replacing it may cause GRUB to crash unexpectedly.
This fixes obvious problems like "loopback d (d)/somefile". Its not too
onerous to force the user to delete the loopback first with the "-d" switch.
Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.
This is preparatory patch.
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
rather than the file it points to. This fixes use of freed memory
if an existing loopback device is replaced.
* grub-core/disk/loopback.c (grub_loopback_open): Store dev in
disk->data, not dev->file.
(grub_loopback_read): Adjust file assignment to match.
Fixes Ubuntu bug #742967.
All users updated.
* disk/loopback.c (grub_loopback): Remove has_partitions.
All users updated.
(options): Remove partitions. All users updated.
* util/grub-fstest.c (fstest): Don't pass "-p" to loopback.
* util/i386/pc/grub-setup.c (setup): copy partition table only when
actual partition table is found.
