[Parted-maintainers] Bug#294520: libparted1.6-13: Incorrect handling of extended partitions

[Anton Zinoviev]

I was able to reproduce this bug on my flash device and the result was
the same as the submitter reported.  In order to reproduce the bug it
seams enough to use parted in the following way:

1. Create an extended partition that ocupies the whole disk.
2. Create a logical partition at the beginning of the ext. partition
3. Create a logical partition at the end of the extended partition
4. Create a logical partition at the remaining space

Create the partitions with different sizes so you can distinguish them
in qtparted.  The result should be like this:

(parted) p                                                                
Disk geometry for /dev/sda: 0kB - 260MB
Disk label type: msdos
Number  Start   End     Size    Type      File system  Flags
1       16kB    260MB   260MB   extended               
5       32kB    49MB    49MB    logical                
7       49MB    200MB   151MB   logical                
6       200MB   260MB   60MB    logical                

(Notice that partition #7 is before #6.)

Now start qtparted.  In order to be safe you can start it as non-root
provided your user has write access to /dev/sda.  The result is that
partition #7 is listed as #6 and #6 is listed as #7.

Since both parted and partman seam not to be affected by this bug I
would recommend to reassign it back to qtparted.

Notice that if you decide not to create the partition at the beginning
of the extended partition and use a partition table like that:

(parted) p                                                                
Disk geometry for /dev/sda: 0kB - 260MB
Disk label type: msdos
Number  Start   End     Size    Type      File system  Flags
1       16kB    260MB   260MB   extended               
6       17kB    208MB   208MB   logical                
5       208MB   260MB   52MB    logical                

then qtparted will be unable to work with this partition table at all.

Anton Zinoviev