* [PATCH] tracing: Consider the NULL character when validating the event length
@ 2024-10-07 13:51 Leo Yan
2024-10-07 14:22 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Leo Yan @ 2024-10-07 13:51 UTC (permalink / raw)
To: Steven Rostedt, Masami Hiramatsu, Mathieu Desnoyers, Dave.Martin,
linux-kernel, linux-trace-kernel
Cc: Leo Yan
strlen() returns a string length excluding the null byte. This commit
adds 1 to account for the NULL terminating character when checking if an
event string is within the maximum length.
Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
kernel/trace/trace_probe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 39877c80d6cb..376ba56c3680 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -276,7 +276,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
}
trace_probe_log_err(offset, NO_EVENT_NAME);
return -EINVAL;
- } else if (len > MAX_EVENT_NAME_LEN) {
+ } else if (len + 1 > MAX_EVENT_NAME_LEN) {
trace_probe_log_err(offset, EVENT_TOO_LONG);
return -EINVAL;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing: Consider the NULL character when validating the event length
2024-10-07 13:51 [PATCH] tracing: Consider the NULL character when validating the event length Leo Yan
@ 2024-10-07 14:22 ` Steven Rostedt
2024-10-07 14:33 ` Leo Yan
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2024-10-07 14:22 UTC (permalink / raw)
To: Leo Yan
Cc: Masami Hiramatsu, Mathieu Desnoyers, Dave.Martin, linux-kernel,
linux-trace-kernel
On Mon, 7 Oct 2024 14:51:26 +0100
Leo Yan <leo.yan@arm.com> wrote:
> strlen() returns a string length excluding the null byte. This commit
> adds 1 to account for the NULL terminating character when checking if an
> event string is within the maximum length.
>
> Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
> kernel/trace/trace_probe.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 39877c80d6cb..376ba56c3680 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -276,7 +276,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
> }
> trace_probe_log_err(offset, NO_EVENT_NAME);
> return -EINVAL;
> - } else if (len > MAX_EVENT_NAME_LEN) {
> + } else if (len + 1 > MAX_EVENT_NAME_LEN) {
Usually, the check is:
} else if (len >= MAX_EVENT_NAME_LEN) {
Which is a better way to check max length.
-- Steve
> trace_probe_log_err(offset, EVENT_TOO_LONG);
> return -EINVAL;
> }
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing: Consider the NULL character when validating the event length
2024-10-07 14:22 ` Steven Rostedt
@ 2024-10-07 14:33 ` Leo Yan
0 siblings, 0 replies; 3+ messages in thread
From: Leo Yan @ 2024-10-07 14:33 UTC (permalink / raw)
To: Steven Rostedt
Cc: Masami Hiramatsu, Mathieu Desnoyers, Dave.Martin, linux-kernel,
linux-trace-kernel
On 10/7/24 15:22, Steven Rostedt wrote:
> Warning: EXTERNAL SENDER, use caution when opening links or attachments.
>
>
> On Mon, 7 Oct 2024 14:51:26 +0100
> Leo Yan <leo.yan@arm.com> wrote:
>
>> strlen() returns a string length excluding the null byte. This commit
>> adds 1 to account for the NULL terminating character when checking if an
>> event string is within the maximum length.
>>
>> Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
>> Signed-off-by: Leo Yan <leo.yan@arm.com>
>> ---
>> kernel/trace/trace_probe.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
>> index 39877c80d6cb..376ba56c3680 100644
>> --- a/kernel/trace/trace_probe.c
>> +++ b/kernel/trace/trace_probe.c
>> @@ -276,7 +276,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
>> }
>> trace_probe_log_err(offset, NO_EVENT_NAME);
>> return -EINVAL;
>> - } else if (len > MAX_EVENT_NAME_LEN) {
>> + } else if (len + 1 > MAX_EVENT_NAME_LEN) {
>
> Usually, the check is:
>
> } else if (len >= MAX_EVENT_NAME_LEN) {
>
> Which is a better way to check max length.
Will update. Thanks for suggestion.
Leo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-10-07 13:51 [PATCH] tracing: Consider the NULL character when validating the event length Leo Yan
2024-10-07 14:22 ` Steven Rostedt
2024-10-07 14:33 ` Leo Yan
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