From: Li Jinyue <lijinyue@huawei.com>
To: <tglx@linutronix.de>, <mingo@redhat.com>, <peterz@infradead.org>,
<dvhart@infradead.org>
Cc: <linux-kernel@vger.kernel.org>, Li Jinyue <lijinyue@huawei.com>
Subject: [PATCH] futex: Prevent overflow by strengthen input validation
Date: Thu, 14 Dec 2017 17:04:54 +0800
Message-ID: <1513242294-31786-1-git-send-email-lijinyue@huawei.com> (raw)
UBSAN reports signed integer overflow in kernel/futex.c
Test log as follows:
UBSAN: Undefined behaviour in kernel/futex.c:2041:18
signed integer overflow:
0 - -2147483648 cannot be represented in type 'int'
To prevent overflow, we don't allow nr_wake and nr_requeue to accept
a negative entropy value.
Signed-off-by: Li Jinyue <lijinyue@huawei.com>
---
kernel/futex.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index 57d0b36..0abfa09 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1878,6 +1878,9 @@ static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
struct futex_q *this, *next;
DEFINE_WAKE_Q(wake_q);
+ if (nr_wake < 0 || nr_requeue < 0)
+ return -EINVAL;
+
/*
* When PI not supported: return -ENOSYS if requeue_pi is true,
* consequently the compiler knows requeue_pi is always false past
--
1.6.0.2
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Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-14 9:04 Li Jinyue [this message]
2018-01-14 18:07 ` [tip:locking/urgent] " tip-bot for Li Jinyue
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