4.9-stable review patch. If anyone has any objections, please let me know.
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From: Li Jinyue lijinyue@huawei.com
commit fbe0e839d1e22d88810f3ee3e2f1479be4c0aa4a upstream.
UBSAN reports signed integer overflow in kernel/futex.c:
UBSAN: Undefined behaviour in kernel/futex.c:2041:18 signed integer overflow: 0 - -2147483648 cannot be represented in type 'int'
Add a sanity check to catch negative values of nr_wake and nr_requeue.
Signed-off-by: Li Jinyue lijinyue@huawei.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: peterz@infradead.org Cc: dvhart@infradead.org Link: https://lkml.kernel.org/r/1513242294-31786-1-git-send-email-lijinyue@huawei.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/futex.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/futex.c +++ b/kernel/futex.c @@ -1711,6 +1711,9 @@ static int futex_requeue(u32 __user *uad struct futex_q *this, *next; WAKE_Q(wake_q);
+ if (nr_wake < 0 || nr_requeue < 0) + return -EINVAL; + if (requeue_pi) { /* * Requeue PI only works on two distinct uaddrs. This