From 910689e4656a069ce548a334827f759f162bd9a9 Mon Sep 17 00:00:00 2001 From: Natalia Petrova Date: Wed, 11 Jan 2023 15:04:09 +0300 Subject: [PATCH] trace_events_hist: add check for return value of 'create_hist_field' stable inclusion from stable-v5.10.166 commit 886aa449235f478e262bbd5dcdee6ed6bc202949 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7TH9O Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=886aa449235f478e262bbd5dcdee6ed6bc202949 -------------------------------- commit 8b152e9150d07a885f95e1fd401fc81af202d9a4 upstream. 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: 30350d65ac56 ("tracing: Add variable support to hist triggers") Signed-off-by: Natalia Petrova Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman Signed-off-by: sanglipeng --- kernel/trace/trace_events_hist.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 0ae3e4454ff2..ccc99cd23f3c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1646,6 +1646,8 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, unsigned long fl = flags & ~HIST_FIELD_FL_LOG2; hist_field->fn = hist_field_log2; 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(hist_field->operands[0]->type, GFP_KERNEL); if (!hist_field->type) -- GitLab