vmdk files cause qemu-img to consume lots of time and memory

[Richard Jones]

The two attached files cause 'qemu-img info' to consume lots of time and memory. Around 10-12 seconds of CPU time, and around 3-4 GB of heap.

$ /usr/bin/time ~/d/qemu/qemu-img info afl10.img
qemu-img: Can't get size of device 'image': File too large
0.40user 11.57system 0:12.03elapsed 99%CPU (0avgtext+0avgdata 4197804maxresident)k
56inputs+0outputs (0major+1045672minor)pagefaults 0swaps

$ /usr/bin/time ~/d/qemu/qemu-img info afl11.img
image: afl11.img
file format: vmdk
virtual size: 12802T (14075741666803712 bytes)
disk size: 4.0K
cluster_size: 65536
Format specific information:
    cid: 4294967295
    parent cid: 4294967295
    create type: monolithicSparse
    extents:
        [0]:
            virtual size: 14075741666803712
            filename: afl11.img
            cluster size: 65536
            format:
0.29user 9.10system 0:09.43elapsed 99%CPU (0avgtext+0avgdata 3297360maxresident)k
8inputs+0outputs (0major+820507minor)pagefaults 0swaps

[Richard Jones (rjones-redhat)]

Both files were found by using american-fuzzy-lop.

[Thomas Huth (th-huth)]

Looking through old bug tickets... can you still reproduce this issue with the latest version of QEMU? Or could we close this ticket nowadays?

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]