From: Nikita Kiryushin <kiryushin@ancud.ru>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Nikita Kiryushin <kiryushin@ancud.ru>,
Frederic Weisbecker <frederic@kernel.org>,
Neeraj Upadhyay <quic_neeraju@quicinc.com>,
Joel Fernandes <joel@joelfernandes.org>,
Josh Triplett <josh@joshtriplett.org>,
Boqun Feng <boqun.feng@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
lvc-project@linuxtesting.org
Subject: [PATCH] rcu: Fix buffer overlow in print_cpu_stall_info()
Date: Thu, 28 Mar 2024 21:19:14 +0300 [thread overview]
Message-ID: <20240328181914.869332-1-kiryushin@ancud.ru> (raw)
rcuc info output in print_cpu_stall_info() contains
posiible buffer overflow in the case of huge jiffies
difference. The situation seems improbable, but, buffer
overflow, still. Also, unsigned jiffies difference printed
as (signed) %ld (which can be a bad format, if the values
are huge).
Change sprintf to snprintf and change %ld to %lu in format.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 245a62982502 ("rcu: Dump rcuc kthread status for CPUs not reporting quiescent state")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
---
kernel/rcu/tree_stall.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index 5d666428546b..d4542c6e7c60 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -504,7 +504,7 @@ static void print_cpu_stall_info(int cpu)
rcu_dynticks_in_eqs(rcu_dynticks_snap(cpu));
rcuc_starved = rcu_is_rcuc_kthread_starving(rdp, &j);
if (rcuc_starved)
- sprintf(buf, " rcuc=%ld jiffies(starved)", j);
+ snprintf(buf, sizeof(buf), " rcuc=%lu jiffies(starved)", j);
pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%04x/%ld/%#lx softirq=%u/%u fqs=%ld%s%s\n",
cpu,
"O."[!!cpu_online(cpu)],
--
2.34.1
next reply other threads:[~2024-03-28 18:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-28 18:19 Nikita Kiryushin [this message]
2024-03-29 17:43 ` [PATCH] rcu: Fix buffer overlow in print_cpu_stall_info() Paul E. McKenney
2024-03-29 17:56 ` Nikita Kiryushin
2024-03-29 18:32 ` Steven Rostedt
2024-03-29 22:21 ` Paul E. McKenney
2024-04-01 18:54 ` [PATCH v2] " Nikita Kiryushin
2024-04-01 19:05 ` Steven Rostedt
2024-04-01 19:43 ` [PATCH v3] " Nikita Kiryushin
2024-04-01 20:03 ` Steven Rostedt
2024-04-01 20:54 ` Paul E. McKenney
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