From: Dan Carpenter Date: Fri, 6 Nov 2020 08:52:05 +0000 (+0300) Subject: futex: Don't enable IRQs unconditionally in put_pi_state() X-Git-Tag: v5.4.78~32 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=2192d905df0d540f6f3240046bcb06c53bcf5016;p=users%2Fdwmw2%2Flinux.git futex: Don't enable IRQs unconditionally in put_pi_state() commit 1e106aa3509b86738769775969822ffc1ec21bf4 upstream. The exit_pi_state_list() function calls put_pi_state() with IRQs disabled and is not expecting that IRQs will be enabled inside the function. Use the _irqsave() variant so that IRQs are restored to the original state instead of being enabled unconditionally. Fixes: 153fbd1226fb ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races") Signed-off-by: Dan Carpenter Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201106085205.GA1159983@mwanda Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/futex.c b/kernel/futex.c index 9c4f9b868a491..b6dec5f79370c 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -880,8 +880,9 @@ static void put_pi_state(struct futex_pi_state *pi_state) */ if (pi_state->owner) { struct task_struct *owner; + unsigned long flags; - raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); + raw_spin_lock_irqsave(&pi_state->pi_mutex.wait_lock, flags); owner = pi_state->owner; if (owner) { raw_spin_lock(&owner->pi_lock); @@ -889,7 +890,7 @@ static void put_pi_state(struct futex_pi_state *pi_state) raw_spin_unlock(&owner->pi_lock); } rt_mutex_proxy_unlock(&pi_state->pi_mutex, owner); - raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); + raw_spin_unlock_irqrestore(&pi_state->pi_mutex.wait_lock, flags); } if (current->pi_state_cache) {