diff mbox series

[v3,10/21] trace-cmd library: Fix possible memory leak in read_event_files()

Message ID 20210914131232.3964615-11-tz.stoyanov@gmail.com (mailing list archive)
State Superseded
Headers show
Series trace-cmd fixes and clean-ups | expand

Commit Message

Tzvetomir Stoyanov (VMware) Sept. 14, 2021, 1:12 p.m. UTC
Some error paths in read_event_files() may lead to a memory leak.
Improved the error handling of this internal function to avoid it.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/trace-cmd/trace-input.c | 39 ++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

Comments

Steven Rostedt Oct. 4, 2021, 3:47 p.m. UTC | #1
On Tue, 14 Sep 2021 16:12:21 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> Some error paths in read_event_files() may lead to a memory leak.
> Improved the error handling of this internal function to avoid it.
> 
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
>  lib/trace-cmd/trace-input.c | 39 ++++++++++++++++++-------------------
>  1 file changed, 19 insertions(+), 20 deletions(-)
> 
> diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
> index 94fd8693..32358ce9 100644
> --- a/lib/trace-cmd/trace-input.c
> +++ b/lib/trace-cmd/trace-input.c
> @@ -645,7 +645,7 @@ out:
>  static int read_event_files(struct tracecmd_input *handle, const char *regex)
>  {
>  	unsigned long long size;
> -	char *system;
> +	char *system = NULL;
>  	regex_t spreg;
>  	regex_t epreg;
>  	regex_t *sreg = NULL;
> @@ -670,13 +670,16 @@ static int read_event_files(struct tracecmd_input *handle, const char *regex)
>  			return -1;
>  	}
>  
> -	if (read4(handle, &systems) < 0)
> -		return -1;
> +	ret = read4(handle, &systems);
> +	if (ret < 0)
> +		goto out;
>  
>  	for (i = 0; i < systems; i++) {
>  		system = read_string(handle);
> -		if (!system)
> -			return -1;
> +		if (!system) {
> +			ret = -1;
> +			goto out;
> +		}
>  
>  		sys_printed = 0;
>  		print_all = 0;
> @@ -703,39 +706,35 @@ static int read_event_files(struct tracecmd_input *handle, const char *regex)
>  			}
>  		}
>  
> -		if (read4(handle, &count) < 0)
> -			goto failed;
> +		ret = read4(handle, &count);
> +		if (ret < 0)
> +			goto out;
>  
>  		for (x=0; x < count; x++) {
> -			if (read8(handle, &size) < 0)
> -				goto failed;
> +			ret = read8(handle, &size);
> +			if (ret < 0)
> +				goto out;
>  
>  			ret = read_event_file(handle, system, size,
>  					      print_all, &sys_printed,
>  					      reg);
>  			if (ret < 0)
> -				goto failed;
> +				goto out;
>  		}
>  		free(system);
> -	}
> -
> -	if (sreg) {
> -		regfree(sreg);
> -		regfree(ereg);
> +		system = NULL;
>  	}

Nit, I would have placed "system = NULL;" outside the loop as it gets set
first thing in the loop, but that's just my preference ;-)

Other than that, the patch looks good. No need to update it.

-- Steve


>  
>  	handle->file_state = TRACECMD_FILE_ALL_EVENTS;
> -
> -	return 0;
> -
> - failed:
> +	ret = 0;
> + out:
>  	if (sreg) {
>  		regfree(sreg);
>  		regfree(ereg);
>  	}
>  
>  	free(system);
> -	return -1;
> +	return ret;
>  }
>  
>  static int read_proc_kallsyms(struct tracecmd_input *handle)
diff mbox series

Patch

diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 94fd8693..32358ce9 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -645,7 +645,7 @@  out:
 static int read_event_files(struct tracecmd_input *handle, const char *regex)
 {
 	unsigned long long size;
-	char *system;
+	char *system = NULL;
 	regex_t spreg;
 	regex_t epreg;
 	regex_t *sreg = NULL;
@@ -670,13 +670,16 @@  static int read_event_files(struct tracecmd_input *handle, const char *regex)
 			return -1;
 	}
 
-	if (read4(handle, &systems) < 0)
-		return -1;
+	ret = read4(handle, &systems);
+	if (ret < 0)
+		goto out;
 
 	for (i = 0; i < systems; i++) {
 		system = read_string(handle);
-		if (!system)
-			return -1;
+		if (!system) {
+			ret = -1;
+			goto out;
+		}
 
 		sys_printed = 0;
 		print_all = 0;
@@ -703,39 +706,35 @@  static int read_event_files(struct tracecmd_input *handle, const char *regex)
 			}
 		}
 
-		if (read4(handle, &count) < 0)
-			goto failed;
+		ret = read4(handle, &count);
+		if (ret < 0)
+			goto out;
 
 		for (x=0; x < count; x++) {
-			if (read8(handle, &size) < 0)
-				goto failed;
+			ret = read8(handle, &size);
+			if (ret < 0)
+				goto out;
 
 			ret = read_event_file(handle, system, size,
 					      print_all, &sys_printed,
 					      reg);
 			if (ret < 0)
-				goto failed;
+				goto out;
 		}
 		free(system);
-	}
-
-	if (sreg) {
-		regfree(sreg);
-		regfree(ereg);
+		system = NULL;
 	}
 
 	handle->file_state = TRACECMD_FILE_ALL_EVENTS;
-
-	return 0;
-
- failed:
+	ret = 0;
+ out:
 	if (sreg) {
 		regfree(sreg);
 		regfree(ereg);
 	}
 
 	free(system);
-	return -1;
+	return ret;
 }
 
 static int read_proc_kallsyms(struct tracecmd_input *handle)