[PATCH 4.9.y 0/1] Bugfix for 781691c797de ("futex: Avoid violating the 10th rule of futex")

From: Zheng Yejian
Date: Tue Feb 23 2021 - 09:36:13 EST


This patch may fix the following bug:

Link:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/?h=linux-4.9.y&id=5b1d078507bd33ebf6c2083fa363cf5832809c19

> static int __fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
> struct task_struct *argowner)
> {
> struct futex_pi_state *pi_state = q->pi_state;
> struct task_struct *oldowner, *newowner;
> u32 uval, curval, newval, newtid;
> int err = 0;
>
> oldowner = pi_state->owner;
>
> /* Owner died? */
> if (!pi_state->owner)
> newtid |= FUTEX_OWNER_DIED;
Variable "newtid" is used without initialized.

Peter Zijlstra (1):
futex: Fix OWNER_DEAD fixup

kernel/futex.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

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2.25.4