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author | Anthony Liguori <aliguori@us.ibm.com> | 2012-06-27 07:37:54 -0500 |
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committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-06-27 16:26:59 -0500 |
commit | 7de3abe505e34398cef5bddf6c4d0bd9ee47007f (patch) | |
tree | 6c0c64a3d067116f78673ac9d13d1f2e43896657 | |
parent | d24b569a4162c54426ab5088637b824f54f6ac16 (diff) | |
download | hqemu-7de3abe505e34398cef5bddf6c4d0bd9ee47007f.zip hqemu-7de3abe505e34398cef5bddf6c4d0bd9ee47007f.tar.gz |
qdev: fix use-after-free in the error path of qdev_init_nofail
From Markus:
Before:
$ qemu-system-x86_64 -display none -drive if=ide
qemu-system-x86_64: Device needs media, but drive is empty
qemu-system-x86_64: Initialization of device ide-hd failed
[Exit 1 ]
After:
$ qemu-system-x86_64 -display none -drive if=ide
qemu-system-x86_64: Device needs media, but drive is empty
Segmentation fault (core dumped)
[Exit 139 (SIGSEGV)]
This error always existed as qdev_init() frees the object. But QOM
goes a bit further and purposefully sets the class pointer to NULL to
help find use-after-free. It worked :-)
Cc: Andreas Faerber <afaerber@suse.de>
Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r-- | hw/qdev.c | 5 |
1 files changed, 3 insertions, 2 deletions
@@ -258,9 +258,10 @@ int qdev_simple_unplug_cb(DeviceState *dev) way is somewhat unclean, and best avoided. */ void qdev_init_nofail(DeviceState *dev) { + const char *typename = object_get_typename(OBJECT(dev)); + if (qdev_init(dev) < 0) { - error_report("Initialization of device %s failed", - object_get_typename(OBJECT(dev))); + error_report("Initialization of device %s failed", typename); exit(1); } } |