From: Dan Carpenter <dan.carpenter@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
"Paul E. McKenney" <paulmck@kernel.org>,
Kaitao Cheng <pilgrimtao@gmail.com>,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] kernel/smp: Fix an off by one in csd_lock_wait_toolong()
Date: Thu, 09 Jul 2020 10:48:18 +0000 [thread overview]
Message-ID: <20200709104818.GC20875@mwanda> (raw)
The __per_cpu_offset[] array has "nr_cpu_ids" elements so change the >
>= to prevent a read one element beyond the end of the array.
Fixes: 0504bc41a62c ("kernel/smp: Provide CSD lock timeout diagnostics")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
kernel/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/smp.c b/kernel/smp.c
index 78b602cae6c2..f49966713ac3 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -171,7 +171,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t
*bug_id = atomic_inc_return(&csd_bug_count);
cpu = csd_lock_wait_getcpu(csd);
smp_mb(); // No stale cur_csd values!
- if (WARN_ONCE(cpu < 0 || cpu > nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu))
+ if (WARN_ONCE(cpu < 0 || cpu >= nr_cpu_ids, "%s: cpu = %d\n", __func__, cpu))
cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, 0));
else
cpu_cur_csd = READ_ONCE(per_cpu(cur_csd, cpu));
--
2.27.0
next reply other threads:[~2020-07-09 10:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 10:48 Dan Carpenter [this message]
2020-07-09 10:59 ` [PATCH] kernel/smp: Fix an off by one in csd_lock_wait_toolong() Peter Zijlstra
2020-07-09 11:49 ` Sebastian Andrzej Siewior
2020-07-09 14:36 ` Paul E. McKenney
2020-07-09 14:32 ` Paul E. McKenney
2020-07-09 16:59 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200709104818.GC20875@mwanda \
--to=dan.carpenter@oracle.com \
--cc=bigeasy@linutronix.de \
--cc=kernel-janitors@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=pilgrimtao@gmail.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).