From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 15 Dec 2020 14:30:53 +0000 (-0500)
Subject: Fix: memory and fd leaks in error counter
X-Git-Tag: v2.13.0-rc1~390
X-Git-Url: http://git.lttng.org/?p=lttng-ust.git;a=commitdiff_plain;h=d61ad9ef7bc9a9650ae9e2793ff7e3afe816a670

Fix: memory and fd leaks in error counter

Use a regular pattern for all commands:

If the command callback takes ownership of a pointer or file descriptor,
it sets them to NULL or -1. Therefore, the caller can always try to free
the pointer, or close it if it is greater or equal to 0.

This eliminates memory and fd leaks on error.

Change-Id: I4916920095526c166636c6a432b95fdd6fd1ca4b
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index 682992ca..8d90e2c3 100644
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -1203,6 +1203,7 @@ int handle_message(struct sock_info *sock_info,
 					&args, sock_info);
 		else
 			ret = -ENOSYS;
+		free(args.counter.counter_data);
 		break;
 	}
 	case LTTNG_UST_COUNTER_GLOBAL:
@@ -1220,6 +1221,16 @@ int handle_message(struct sock_info *sock_info,
 					&args, sock_info);
 		else
 			ret = -ENOSYS;
+		if (args.counter_shm.shm_fd >= 0) {
+			int close_ret;
+
+			lttng_ust_lock_fd_tracker();
+			close_ret = close(args.counter_shm.shm_fd);
+			lttng_ust_unlock_fd_tracker();
+			args.counter_shm.shm_fd = -1;
+			if (close_ret)
+				PERROR("close");
+		}
 		break;
 	}
 	case LTTNG_UST_COUNTER_CPU:
@@ -1237,6 +1248,16 @@ int handle_message(struct sock_info *sock_info,
 					&args, sock_info);
 		else
 			ret = -ENOSYS;
+		if (args.counter_shm.shm_fd >= 0) {
+			int close_ret;
+
+			lttng_ust_lock_fd_tracker();
+			close_ret = close(args.counter_shm.shm_fd);
+			lttng_ust_unlock_fd_tracker();
+			args.counter_shm.shm_fd = -1;
+			if (close_ret)
+				PERROR("close");
+		}
 		break;
 	}
 	case LTTNG_UST_EVENT_NOTIFIER_CREATE: