|
 |
a799a51 |
From 137e84f68da06666ebf7f391766cc6209ce1c39c Mon Sep 17 00:00:00 2001
|
|
|
a799a51 |
From: Jon Maloy <jmaloy@redhat.com>
|
|
|
a799a51 |
Date: Tue, 9 May 2023 10:29:03 -0400
|
|
|
a799a51 |
Subject: [PATCH 13/21] async: avoid use-after-free on re-entrancy guard
|
|
|
a799a51 |
|
|
|
a799a51 |
RH-Author: Jon Maloy <jmaloy@redhat.com>
|
|
|
a799a51 |
RH-MergeRequest: 165: memory: prevent dma-reentracy issues
|
|
|
a799a51 |
RH-Jira: RHEL-516
|
|
|
a799a51 |
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
|
a799a51 |
RH-Commit: [9/13] d4b957108aaacf4a597122aaeeaa8e56985f1fca (jmaloy/jmaloy-qemu-kvm-2)
|
|
|
a799a51 |
|
|
|
a799a51 |
Jira: https://issues.redhat.com/browse/RHEL-516
|
|
|
a799a51 |
Upstream: Merged
|
|
|
a799a51 |
CVE: CVE-2023-2680
|
|
|
a799a51 |
|
|
|
a799a51 |
commit 7915bd06f25e1803778081161bf6fa10c42dc7cd
|
|
|
a799a51 |
Author: Alexander Bulekov <alxndr@bu.edu>
|
|
|
a799a51 |
Date: Mon May 1 10:19:56 2023 -0400
|
|
|
a799a51 |
|
|
|
a799a51 |
async: avoid use-after-free on re-entrancy guard
|
|
|
a799a51 |
|
|
|
a799a51 |
A BH callback can free the BH, causing a use-after-free in aio_bh_call.
|
|
|
a799a51 |
Fix that by keeping a local copy of the re-entrancy guard pointer.
|
|
|
a799a51 |
|
|
|
a799a51 |
Buglink: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=58513
|
|
|
a799a51 |
Fixes: 9c86c97f12 ("async: Add an optional reentrancy guard to the BH API")
|
|
|
a799a51 |
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
|
|
|
a799a51 |
Message-Id: <20230501141956.3444868-1-alxndr@bu.edu>
|
|
|
a799a51 |
Reviewed-by: Thomas Huth <thuth@redhat.com>
|
|
|
a799a51 |
Signed-off-by: Thomas Huth <thuth@redhat.com>
|
|
|
a799a51 |
|
|
|
a799a51 |
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
|
|
|
a799a51 |
---
|
|
|
a799a51 |
util/async.c | 14 ++++++++------
|
|
|
a799a51 |
1 file changed, 8 insertions(+), 6 deletions(-)
|
|
|
a799a51 |
|
|
|
a799a51 |
diff --git a/util/async.c b/util/async.c
|
|
|
a799a51 |
index a9b528c370..cd1a1815f9 100644
|
|
|
a799a51 |
--- a/util/async.c
|
|
|
a799a51 |
+++ b/util/async.c
|
|
|
a799a51 |
@@ -156,18 +156,20 @@ void aio_bh_call(QEMUBH *bh)
|
|
|
a799a51 |
{
|
|
|
a799a51 |
bool last_engaged_in_io = false;
|
|
|
a799a51 |
|
|
|
a799a51 |
- if (bh->reentrancy_guard) {
|
|
|
a799a51 |
- last_engaged_in_io = bh->reentrancy_guard->engaged_in_io;
|
|
|
a799a51 |
- if (bh->reentrancy_guard->engaged_in_io) {
|
|
|
a799a51 |
+ /* Make a copy of the guard-pointer as cb may free the bh */
|
|
|
a799a51 |
+ MemReentrancyGuard *reentrancy_guard = bh->reentrancy_guard;
|
|
|
a799a51 |
+ if (reentrancy_guard) {
|
|
|
a799a51 |
+ last_engaged_in_io = reentrancy_guard->engaged_in_io;
|
|
|
a799a51 |
+ if (reentrancy_guard->engaged_in_io) {
|
|
|
a799a51 |
trace_reentrant_aio(bh->ctx, bh->name);
|
|
|
a799a51 |
}
|
|
|
a799a51 |
- bh->reentrancy_guard->engaged_in_io = true;
|
|
|
a799a51 |
+ reentrancy_guard->engaged_in_io = true;
|
|
|
a799a51 |
}
|
|
|
a799a51 |
|
|
|
a799a51 |
bh->cb(bh->opaque);
|
|
|
a799a51 |
|
|
|
a799a51 |
- if (bh->reentrancy_guard) {
|
|
|
a799a51 |
- bh->reentrancy_guard->engaged_in_io = last_engaged_in_io;
|
|
|
a799a51 |
+ if (reentrancy_guard) {
|
|
|
a799a51 |
+ reentrancy_guard->engaged_in_io = last_engaged_in_io;
|
|
|
a799a51 |
}
|
|
|
a799a51 |
}
|
|
|
a799a51 |
|
|
|
a799a51 |
--
|
|
|
a799a51 |
2.39.3
|
|
|
a799a51 |
|