From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Mon, 3 Feb 2020 19:34:53 +0000 (-0500)
Subject: Fix: trace-chunk: dereference after NULL check
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=a3a75bf4721736ec16c30ee70de95e773fedf53b

Fix: trace-chunk: dereference after NULL check

old_path is used directly even though it is checked for NULL. The
situation highlighted by Coverity does not appear to be possible given
the current use of the API. However, it should still be checked to
catch future errors (or current bugs).

1412200 Dereference after null check

Either the check against null is unnecessary, or there may be a null
pointer dereference.

In lttng_trace_chunk_rename_path_no_lock: Pointer is checked against
null but then dereferenced anyway (CWE-476)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I991231cc636eaed98cb84eec08a5072748ff9ef4
---

diff --git a/src/common/trace-chunk.c b/src/common/trace-chunk.c
index f909a682f..ea952220b 100644
--- a/src/common/trace-chunk.c
+++ b/src/common/trace-chunk.c
@@ -859,7 +859,7 @@ enum lttng_trace_chunk_status lttng_trace_chunk_rename_path_no_lock(
 		 */
 		chunk->chunk_directory = rename_directory;
 		rename_directory = NULL;
-	} else {
+	} else if (old_path) {
 		size_t i, count = lttng_dynamic_pointer_array_get_count(
 				&chunk->top_level_directories);
 		const bool reference_acquired = lttng_directory_handle_get(
@@ -908,6 +908,10 @@ enum lttng_trace_chunk_status lttng_trace_chunk_rename_path_no_lock(
 			ret = -1;
 			goto end;
 		}
+	} else {
+		/* Unexpected !old_path && !path. */
+		status = LTTNG_TRACE_CHUNK_STATUS_INVALID_ARGUMENT;
+		goto end;
 	}
 
 skip_move: