From: Keita Suzuki keitasuzuki.park@sslab.ics.keio.ac.jp
stable inclusion from stable-v5.10.121 commit 058cb6d86b9789377216c936506b346aaa1eb581 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 99696a2592bca641eb88cc9a80c90e591afebd0f upstream.
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.ic...
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- kernel/trace/trace_events_hist.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index eb7200699cf6..3ed1723b68d5 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1789,8 +1789,11 @@ 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; }