From: Cyrill Gorcunov <gorcunov@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andrey Vagin <avagin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v2] fs/proc: timers -- Test for potential index overflow
Date: Fri, 9 Nov 2018 14:31:53 +0300 [thread overview]
Message-ID: <20181109113153.GJ13195@uranus.lan> (raw)
In-Reply-To: <20181109092810.GF13195@uranus.lan>
When showing timer's notify symbolic name make sure we never fetch a value
sitting outside of the names array. Though the former issue displaying
timer->it_sigev_notify has been fixed by Thomas in commit cef31d9af9082434,
better to make sure we won't hit it again on furher modifications.
v2: Use explicit index overflow test (by tglx@). Since
it should never happen add warn-once to notify.
Cc: Andrey Vagin <avagin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
fs/proc/base.c | 6 ++++++
1 file changed, 6 insertions(+)
Index: linux-ml.git/fs/proc/base.c
===================================================================
--- linux-ml.git.orig/fs/proc/base.c
+++ linux-ml.git/fs/proc/base.c
@@ -2297,6 +2297,12 @@ static int show_timer(struct seq_file *m
timer = list_entry((struct list_head *)v, struct k_itimer, list);
notify = timer->it_sigev_notify;
+ if ((notify & ~SIGEV_THREAD_ID) >= ARRAY_SIZE(nstr)) {
+ WARN_ONCE(1, "timer: Bad signal notify mode %#x on ID %d\n",
+ notify, timer->it_id);
+ return -EINVAL;
+ }
+
seq_printf(m, "ID: %d\n", timer->it_id);
seq_printf(m, "signal: %d/%px\n",
timer->sigq->info.si_signo,
next prev parent reply other threads:[~2018-11-09 11:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-01 18:27 [PATCH] posix-timers: Use array safe helper when fetching notification symbolic name Cyrill Gorcunov
2018-11-09 9:18 ` Thomas Gleixner
2018-11-09 9:28 ` Cyrill Gorcunov
2018-11-09 11:31 ` Cyrill Gorcunov [this message]
2018-12-21 20:28 ` [PATCH v2] fs/proc: timers -- Test for potential index overflow Cyrill Gorcunov
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