--- /dev/null
+From 5a07168d8d89b00fe1760120714378175b3ef992 Mon Sep 17 00:00:00 2001
+From: Chen Jie <chenjie6@huawei.com>
+Date: Fri, 15 Mar 2019 03:44:38 +0000
+Subject: futex: Ensure that futex address is aligned in handle_futex_death()
+
+From: Chen Jie <chenjie6@huawei.com>
+
+commit 5a07168d8d89b00fe1760120714378175b3ef992 upstream.
+
+The futex code requires that the user space addresses of futexes are 32bit
+aligned. sys_futex() checks this in futex_get_keys() but the robust list
+code has no alignment check in place.
+
+As a consequence the kernel crashes on architectures with strict alignment
+requirements in handle_futex_death() when trying to cmpxchg() on an
+unaligned futex address which was retrieved from the robust list.
+
+[ tglx: Rewrote changelog, proper sizeof() based alignement check and add
+ comment ]
+
+Fixes: 0771dfefc9e5 ("[PATCH] lightweight robust futexes: core")
+Signed-off-by: Chen Jie <chenjie6@huawei.com>
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Cc: <dvhart@infradead.org>
+Cc: <peterz@infradead.org>
+Cc: <zengweilin@huawei.com>
+Cc: stable@vger.kernel.org
+Link: https://lkml.kernel.org/r/1552621478-119787-1-git-send-email-chenjie6@huawei.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ kernel/futex.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/kernel/futex.c
++++ b/kernel/futex.c
+@@ -2897,6 +2897,10 @@ int handle_futex_death(u32 __user *uaddr
+ {
+ u32 uval, uninitialized_var(nval), mval;
+
++ /* Futex address must be 32bit aligned */
++ if ((((unsigned long)uaddr) % sizeof(*uaddr)) != 0)
++ return -1;
++
+ retry:
+ if (get_user(uval, uaddr))
+ return -1;