Clean up format data after a failed probe

Make sure that format-specific data is cleaned up after a failed probe.

Since private data may not be even allocated at that point, the cleanup
handlers must check that the pointer is not NULL before dereferencing it.
Add this check to devmem and lkcd cleanup handlers.

Signed-off-by: Petr Tesarik <[email protected]>

src/kdumpfile/devmem.c

@@ -339,6 +339,9 @@ devmem_cleanup(struct kdump_shared *shared)
 {
 	struct devmem_priv *dmp = shared->fmtdata;
 
+	if (!dmp)
+		return;
+
 	if (dmp->ce) {
 		free(dmp->ce[0].data);
 		free(dmp->ce);

src/kdumpfile/lkcd.c

@@ -1070,6 +1070,9 @@ lkcd_cleanup(struct kdump_shared *shared)
 {
 	struct lkcd_priv *lkcdp = shared->fmtdata;
 
+	if (!lkcdp)
+		return;
+
 	free_level1(lkcdp->pfn_level1, lkcdp->l1_size);
 	mutex_destroy(&lkcdp->pfn_block_mutex);
 	if (lkcdp->cbuf_slot >= 0)

src/kdumpfile/open.c

@@ -338,6 +338,8 @@ open_dump(kdump_ctx_t *ctx)
 		ret = ctx->shared->ops->probe(ctx);
 		if (ret == KDUMP_OK)
 			return finish_open_dump(ctx);
+		if (ctx->shared->ops->cleanup)
+			ctx->shared->ops->cleanup(ctx->shared);
 		if (ret != KDUMP_NOPROBE)
 			return ret;