From c3adb58fe0b2db4942f5b2f5d19bc51a29b93a89 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 14 Mar 2014 09:22:48 +0100 Subject: blockdev: Refuse to open encrypted image unless paused Opening an encrypted image takes an additional step: setting the key. Between open and the key set, the image must not be used. We have some protection against accidental use in place: you can't unpause a guest while we're missing keys. You can, however, hot-plug block devices lacking keys into a running guest just fine, or insert media lacking keys. In the latter case, notifying the guest of the insert is delayed until the key is set, which may suffice to protect at least some guests in common usage. This patch makes the protection apply in more cases, in a rather heavy-handed way: it doesn't let you open encrypted images unless we're in a paused state. It doesn't extend the protection to users other than the guest (block jobs?). Use of runstate_check() from block.c is disgusting. Best I can do right now. Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Reviewed-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi --- block.c | 9 ++++++++- stubs/Makefile.objs | 1 + stubs/runstate-check.c | 6 ++++++ tests/qemu-iotests/087 | 17 +++++++++++++++++ tests/qemu-iotests/087.out | 11 ++++++++++- 5 files changed, 42 insertions(+), 2 deletions(-) create mode 100644 stubs/runstate-check.c diff --git a/block.c b/block.c index fae50c95b5..53f5b44fbb 100644 --- a/block.c +++ b/block.c @@ -1388,12 +1388,19 @@ done: ret = -EINVAL; goto close_and_fail; } - QDECREF(options); if (!bdrv_key_required(bs)) { bdrv_dev_change_media_cb(bs, true); + } else if (!runstate_check(RUN_STATE_PRELAUNCH) + && !runstate_check(RUN_STATE_INMIGRATE) + && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ + error_setg(errp, + "Guest must be stopped for opening of encrypted image"); + ret = -EBUSY; + goto close_and_fail; } + QDECREF(options); *pbs = bs; return 0; diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs index 59c5a54239..5ed1d38d70 100644 --- a/stubs/Makefile.objs +++ b/stubs/Makefile.objs @@ -20,6 +20,7 @@ stub-obj-y += mon-set-error.o stub-obj-y += pci-drive-hot-add.o stub-obj-y += qtest.o stub-obj-y += reset.o +stub-obj-y += runstate-check.o stub-obj-y += set-fd-handler.o stub-obj-y += slirp.o stub-obj-y += sysbus.o diff --git a/stubs/runstate-check.c b/stubs/runstate-check.c new file mode 100644 index 0000000000..bd2e3757ae --- /dev/null +++ b/stubs/runstate-check.c @@ -0,0 +1,6 @@ +#include "sysemu/sysemu.h" + +bool runstate_check(RunState state) +{ + return state == RUN_STATE_PRELAUNCH; +} diff --git a/tests/qemu-iotests/087 b/tests/qemu-iotests/087 index 53b6c43bff..a38bb702b3 100755 --- a/tests/qemu-iotests/087 +++ b/tests/qemu-iotests/087 @@ -99,6 +99,23 @@ echo === Encrypted image === echo _make_test_img -o encryption=on $size +run_qemu -S <