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qemu-kvm/SOURCES/kvm-apic-disable-reentrancy...

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1.8 KiB

From 5beea8b889a38aa59259679d7f1ba050f09eb0f0 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 9 May 2023 10:29:03 -0400
Subject: [PATCH 12/21] apic: disable reentrancy detection for apic-msi
RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 165: memory: prevent dma-reentracy issues
RH-Jira: RHEL-516
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [8/13] 329f3b1c02fc42d85c821dd14c70e6b885cf849a (jmaloy/jmaloy-qemu-kvm-2)
Jira: https://issues.redhat.com/browse/RHEL-516
Upstream: Merged
CVE: CVE-2023-2680
commit 50795ee051a342c681a9b45671c552fbd6274db8
Author: Alexander Bulekov <alxndr@bu.edu>
Date: Thu Apr 27 17:10:13 2023 -0400
apic: disable reentrancy detection for apic-msi
As the code is designed for re-entrant calls to apic-msi, mark apic-msi
as reentrancy-safe.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-9-alxndr@bu.edu>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
hw/intc/apic.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 20b5a94073..ac3d47d231 100644
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -885,6 +885,13 @@ static void apic_realize(DeviceState *dev, Error **errp)
memory_region_init_io(&s->io_memory, OBJECT(s), &apic_io_ops, s, "apic-msi",
APIC_SPACE_SIZE);
+ /*
+ * apic-msi's apic_mem_write can call into ioapic_eoi_broadcast, which can
+ * write back to apic-msi. As such mark the apic-msi region re-entrancy
+ * safe.
+ */
+ s->io_memory.disable_reentrancy_guard = true;
+
s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, apic_timer, s);
local_apics[s->id] = s;
--
2.39.3