[PATCH] sched/core: fix buffer overflow in cgroup2 property cpu.max

[Konstantin Khlebnikov]

Add limit into sscanf format string for on-stack buffer.

Fixes: 0d5936344f30 ("sched: Implement interface for cgroup unified hierarchy")
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
 kernel/sched/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 43f44539b88f..3971bc62521d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6968,7 +6968,7 @@ static int __maybe_unused cpu_period_quota_parse(char *buf,
 {
 	char tok[21];	/* U64_MAX */
 
-	if (!sscanf(buf, "%s %llu", tok, periodp))
+	if (sscanf(buf, "%20s %llu", tok, periodp) < 1)
 		return -EINVAL;
 
 	*periodp *= NSEC_PER_USEC;