From 2ca5d34d200f2e224173edd3ed2d152787d6b8fe Mon Sep 17 00:00:00 2001 From: Dmitry Chagin Date: Mon, 1 May 2017 12:25:37 +0000 Subject: [PATCH] Fix NULL pointer dereference in futex_wake_op() in case when the same address specified for arguments uaddr and uaddr2. PR: 218987 Reported by: luke.tw gmail MFC after: 1 week --- sys/compat/linux/linux_futex.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/sys/compat/linux/linux_futex.c b/sys/compat/linux/linux_futex.c index 3075afbc266..7cbdaea6f5a 100644 --- a/sys/compat/linux/linux_futex.c +++ b/sys/compat/linux/linux_futex.c @@ -952,6 +952,11 @@ retry1: args->uaddr, args->val, args->uaddr2, args->val3, args->timeout); + if (args->uaddr == args->uaddr2) { + LIN_SDT_PROBE1(futex, linux_sys_futex, return, EINVAL); + return (EINVAL); + } + retry2: error = futex_get(args->uaddr, NULL, &f, flags | FUTEX_DONTLOCK); if (error) { @@ -959,9 +964,7 @@ retry2: return (error); } - if (args->uaddr != args->uaddr2) - error = futex_get(args->uaddr2, NULL, &f2, - flags | FUTEX_DONTLOCK); + error = futex_get(args->uaddr2, NULL, &f2, flags | FUTEX_DONTLOCK); if (error) { futex_put(f, NULL);