Commit 8b152e91 authored by Natalia Petrova's avatar Natalia Petrova Committed by Steven Rostedt (Google)
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trace_events_hist: add check for return value of 'create_hist_field' 

Function 'create_hist_field' is called recursively at
trace_events_hist.c:1954 and can return NULL-value that's why we have
to check it to avoid null pointer dereference.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru



Cc: stable@vger.kernel.org
Fixes: 30350d65 ("tracing: Add variable support to hist triggers")
Signed-off-by: default avatarNatalia Petrova <n.petrova@fintech.ru>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 685b64e4

kernel/trace/trace_events_hist.c

+2 −0
Original line number Diff line number Diff line
@@ -1988,6 +1988,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, 
		hist_field->fn_num = flags & HIST_FIELD_FL_LOG2 ? HIST_FIELD_FN_LOG2 :

			HIST_FIELD_FN_BUCKET;

		hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);

		if (!hist_field->operands[0])

			goto free;

		hist_field->size = hist_field->operands[0]->size;

		hist_field->type = kstrdup_const(hist_field->operands[0]->type, GFP_KERNEL);

		if (!hist_field->type)