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authorKeita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>2022-04-25 06:37:38 +0000
committerSteven Rostedt (Google) <rostedt@goodmis.org>2022-05-26 21:12:59 -0400
commit99696a2592bca641eb88cc9a80c90e591afebd0f (patch)
treef7099085c0a6fd9675f2ec758c3a76b38bbf2602
parentcb24693d94ceaf658944ad2e922203c0503775d2 (diff)
tracing: Fix potential double free in create_var_ref()
In create_var_ref(), init_var_ref() is called to initialize the fields of variable ref_field, which is allocated in the previous function call to create_hist_field(). Function init_var_ref() allocates the corresponding fields such as ref_field->system, but frees these fields when the function encounters an error. The caller later calls destroy_hist_field() to conduct error handling, which frees the fields and the variable itself. This results in double free of the fields which are already freed in the previous function. Fix this by storing NULL to the corresponding fields when they are freed in init_var_ref(). Link: https://lkml.kernel.org/r/20220425063739.3859998-1-keitasuzuki.park@sslab.ics.keio.ac.jp Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers") CC: stable@vger.kernel.org Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_events_hist.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 038dc591545d..c6a65738feb3 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2093,8 +2093,11 @@ static int init_var_ref(struct hist_field *ref_field,
return err;
free:
kfree(ref_field->system);
+ ref_field->system = NULL;
kfree(ref_field->event_name);
+ ref_field->event_name = NULL;
kfree(ref_field->name);
+ ref_field->name = NULL;
goto out;
}