pstore: Remove filesystem records when backend is unregistered
If a backend was unloaded without having first removed all its
associated records in pstorefs, subsequent removals would crash while
attempting to call into the now missing backend. Add automatic removal
from the tree in pstore_unregister(), so that no references to the
backend remain.
Reported-by: Luis Henriques <lhenriques@suse.com>
Link: https://lore.kernel.org/lkml/87o8yrmv69.fsf@suse.com
Link: https://lore.kernel.org/lkml/20200506152114.50375-11-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 327ee70..398785a 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -657,6 +657,9 @@ void pstore_unregister(struct pstore_info *psi)
del_timer_sync(&pstore_timer);
flush_work(&pstore_work);
+ /* Remove all backend records from filesystem tree. */
+ pstore_put_backend_records(psi);
+
free_buf_for_compression();
psinfo = NULL;