Fix NULL pointer dereference during device removal in ibcore.

As part of ib_uverbs_remove_one which might be triggered upon
reset flow, we trigger IB_EVENT_DEVICE_FATAL event to userspace
application.
If device was removed after uverbs fd was opened but before
ib_uverbs_get_context was called, the event file will be accessed
before it was allocated, result in NULL pointer dereference:

Linux commit:
870201f95fcbd19538aef630393fe9d583eff82e

MFC after:		1 week
Sponsored by:		Mellanox Technologies
This commit is contained in:
hselasky 2018-07-17 09:16:54 +00:00
parent 81f6270976
commit b76d21e418

View File

@ -1274,7 +1274,6 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
kref_get(&file->ref);
mutex_unlock(&uverbs_dev->lists_mutex);
ib_uverbs_event_handler(&file->event_handler, &event);
mutex_lock(&file->cleanup_mutex);
ucontext = file->ucontext;
@ -1291,6 +1290,7 @@ static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
* for example due to freeing the resources
* (e.g mmput).
*/
ib_uverbs_event_handler(&file->event_handler, &event);
ib_dev->disassociate_ucontext(ucontext);
ib_uverbs_cleanup_ucontext(file, ucontext);
}