* [PATCH] tracing: fix double free
@ 2020-09-07 13:58 trix
2020-09-08 14:41 ` Zanussi, Tom
0 siblings, 1 reply; 2+ messages in thread
From: trix @ 2020-09-07 13:58 UTC (permalink / raw)
To: rostedt, mingo, natechancellor, ndesaulniers, tom.zanussi,
baohong.liu
Cc: linux-kernel, clang-built-linux, Tom Rix
From: Tom Rix <trix@redhat.com>
clang static analyzer reports this problem
trace_events_hist.c:3824:3: warning: Attempt to free
released memory
kfree(hist_data->attrs->var_defs.name[i]);
In parse_var_defs() if there is a problem allocating
var_defs.expr, the earlier var_defs.name is freed.
This free is duplicated by free_var_defs() which frees
the rest of the list.
Because free_var_defs() has to run anyway, remove the
second free fom parse_var_defs().
Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers")
Signed-off-by: Tom Rix <trix@redhat.com>
---
kernel/trace/trace_events_hist.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0b933546142e..1b2ef6490229 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3865,7 +3865,6 @@ static int parse_var_defs(struct hist_trigger_data *hist_data)
s = kstrdup(field_str, GFP_KERNEL);
if (!s) {
- kfree(hist_data->attrs->var_defs.name[n_vars]);
ret = -ENOMEM;
goto free;
}
--
2.18.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] tracing: fix double free
2020-09-07 13:58 [PATCH] tracing: fix double free trix
@ 2020-09-08 14:41 ` Zanussi, Tom
0 siblings, 0 replies; 2+ messages in thread
From: Zanussi, Tom @ 2020-09-08 14:41 UTC (permalink / raw)
To: trix, rostedt, mingo, natechancellor, ndesaulniers, baohong.liu
Cc: linux-kernel, clang-built-linux
Hi Tom,
On 9/7/2020 8:58 AM, trix@redhat.com wrote:
> From: Tom Rix <trix@redhat.com>
>
> clang static analyzer reports this problem
>
> trace_events_hist.c:3824:3: warning: Attempt to free
> released memory
> kfree(hist_data->attrs->var_defs.name[i]);
>
> In parse_var_defs() if there is a problem allocating
> var_defs.expr, the earlier var_defs.name is freed.
> This free is duplicated by free_var_defs() which frees
> the rest of the list.
>
> Because free_var_defs() has to run anyway, remove the
> second free fom parse_var_defs().
>
> Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers")
> Signed-off-by: Tom Rix <trix@redhat.com>
Good catch, thanks for fixing this!
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
> ---
> kernel/trace/trace_events_hist.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
> index 0b933546142e..1b2ef6490229 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -3865,7 +3865,6 @@ static int parse_var_defs(struct hist_trigger_data *hist_data)
>
> s = kstrdup(field_str, GFP_KERNEL);
> if (!s) {
> - kfree(hist_data->attrs->var_defs.name[n_vars]);
> ret = -ENOMEM;
> goto free;
> }
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-09-07 13:58 [PATCH] tracing: fix double free trix
2020-09-08 14:41 ` Zanussi, Tom
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