Simple reproducer using only qemu tools: $ qemu-img create -f qcow2 huge.qcow2 $((1024*1024))T Formatting 'huge.qcow2', fmt=qcow2 size=1152921504606846976 encryption=off cluster_size=65536 lazy_refcounts=off $ qemu-io /tmp/huge.qcow2 -c "write $((1024*1024*1024*1024*1024*1024 - 1024)) 512" Segmentation fault
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/865518 Title: qemu segfaults when writing to very large qcow2 disk Status in QEMU: New Bug description: Create a ridiculously large qcow2 disk: qemu-img create -f qcow2 test1.img $((2**63-513)) Attach it to a guest and try to use parted to partition it. This is easy with virt-rescue: you just do: virt-rescue test1.img ><rescue> parted /dev/vda mklabel gpt <-- bang! qemu segfaults here The stack trace is: Program received signal SIGSEGV, Segmentation fault. 0x0000000000434cac in get_cluster_table (bs=0x3193030, offset= 9223372036854764544, new_l2_table=0x591e3c8, new_l2_offset=0x591e3c0, new_l2_index=0x591e408) at block/qcow2-cluster.c:506 506 l2_offset = s->l1_table[l1_index]; (gdb) bt #0 0x0000000000434cac in get_cluster_table (bs=0x3193030, offset= 9223372036854764544, new_l2_table=0x591e3c8, new_l2_offset=0x591e3c0, new_l2_index=0x591e408) at block/qcow2-cluster.c:506 #1 0x000000000043535b in qcow2_alloc_cluster_offset (bs=0x3193030, offset= 9223372036854764544, n_start=106, n_end=126, num=0x591e4e8, m=0x591e470) at block/qcow2-cluster.c:719 #2 0x000000000043b8d4 in qcow2_co_writev (bs=0x3193030, sector_num= 18014398509481962, remaining_sectors=20, qiov=0x4a81ee0) at block/qcow2.c:554 #3 0x0000000000428691 in bdrv_co_rw (opaque=0x38bad10) at block.c:2781 #4 0x000000000046e03a in coroutine_trampoline (i0=59487248, i1=0) at coroutine-ucontext.c:125 #5 0x00000034dc6471b0 in ?? () from /lib64/libc.so.6 #6 0x00007fff76cbb430 in ?? () #7 0x0000000000000000 in ?? () This is qemu from git (8f440cda08c6df574 from 2011-09-29) To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/865518/+subscriptions
