linux-kernel - [PATCH 4.9 19/28] genirq: Prevent use-after-free and work list corruption

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190509181254.290923000@linuxfoundation.org>
Date:   Thu,  9 May 2019 20:42:11 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Prasad Sodagudi <psodagud@...eaurora.org>,
        Thomas Gleixner <tglx@...utronix.de>, marc.zyngier@....com,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 19/28] genirq: Prevent use-after-free and work list corruption

[ Upstream commit 59c39840f5abf4a71e1810a8da71aaccd6c17d26 ]

When irq_set_affinity_notifier() replaces the notifier, then the
reference count on the old notifier is dropped which causes it to be
freed. But nothing ensures that the old notifier is not longer queued
in the work list. If it is queued this results in a use after free and
possibly in work list corruption.

Ensure that the work is canceled before the reference is dropped.

Signed-off-by: Prasad Sodagudi <psodagud@...eaurora.org>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: marc.zyngier@....com
Link: https://lkml.kernel.org/r/1553439424-6529-1-git-send-email-psodagud@codeaurora.org
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 kernel/irq/manage.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index cf94460504bba..be7f489788e27 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -332,8 +332,10 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 	desc->affinity_notify = notify;
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
-	if (old_notify)
+	if (old_notify) {
+		cancel_work_sync(&old_notify->work);
 		kref_put(&old_notify->kref, old_notify->release);
+	}
 
 	return 0;
 }
-- 
2.20.1