From: Tomáš Golembiovský <tgole...@redhat.com> When --offset is set the apparent device size has to be adjusted accordingly. Otherwise client may request read/write beyond the file end which would fail.
Signed-off-by: Tomáš Golembiovský <tgole...@redhat.com> Message-Id: <8a31654cb182932db78b95aae1e904fc2bd1c465.1475698895.git.tgole...@redhat.com> Reviewed-by: Eric Blake <ebl...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- qemu-nbd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/qemu-nbd.c b/qemu-nbd.c index 99297a5..705b95e 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -901,6 +901,14 @@ int main(int argc, char **argv) exit(EXIT_FAILURE); } + if (dev_offset >= fd_size) { + error_report("Offset (%lld) has to be smaller than the image size " + "(%lld)", + (long long int)dev_offset, (long long int)fd_size); + exit(EXIT_FAILURE); + } + fd_size -= dev_offset; + if (partition != -1) { ret = find_partition(blk, partition, &dev_offset, &fd_size); if (ret < 0) { -- 2.7.4