linux-kernel - [PATCH 3.16 312/410] xen/pirq: fix error path cleanup when binding MSIs

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: <lsq.1528380321.731340500@decadent.org.uk>
Date:   Thu, 07 Jun 2018 15:05:21 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Hooman Mirhadi" <mirhadih@...zon.com>,
        "Juergen Gross" <jgross@...e.com>,
        "Boris Ostrovsky" <boris.ostrovsky@...cle.com>,
        "Amit Shah" <aams@...zon.com>,
        "Roger Pau Monne" <roger.pau@...rix.com>
Subject: [PATCH 3.16 312/410] xen/pirq: fix error path cleanup when
 binding MSIs

3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Roger Pau Monne <roger.pau@...rix.com>

commit 910f8befdf5bccf25287d9f1743e3e546bcb7ce0 upstream.

Current cleanup in the error path of xen_bind_pirq_msi_to_irq is
wrong. First of all there's an off-by-one in the cleanup loop, which
can lead to unbinding wrong IRQs.

Secondly IRQs not bound won't be freed, thus leaking IRQ numbers.

Note that there's no need to differentiate between bound and unbound
IRQs when freeing them, __unbind_from_irq will deal with both of them
correctly.

Fixes: 4892c9b4ada9f9 ("xen: add support for MSI message groups")
Reported-by: Hooman Mirhadi <mirhadih@...zon.com>
Signed-off-by: Roger Pau Monné <roger.pau@...rix.com>
Reviewed-by: Amit Shah <aams@...zon.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Signed-off-by: Juergen Gross <jgross@...e.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/xen/events/events_base.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -763,8 +763,8 @@ out:
 	mutex_unlock(&irq_mapping_update_lock);
 	return irq;
 error_irq:
-	for (; i >= 0; i--)
-		__unbind_from_irq(irq + i);
+	while (nvec--)
+		__unbind_from_irq(irq + nvec);
 	mutex_unlock(&irq_mapping_update_lock);
 	return ret;
 }