48 lines
1.8 KiB
Diff
48 lines
1.8 KiB
Diff
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From edf3b2b0a9b9aa992592951a979d1b4642026fe5 Mon Sep 17 00:00:00 2001
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From: Zhang Jiao <zhangjiao2_yewu@cmss.chinamobile.com>
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Date: Fri, 18 Oct 2024 09:12:50 +0800
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Subject: [PATCH] edu: fix DMA range upper bound check
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cheery-pick from 2c5107e1b455d4a157124f021826ead4e04b4aea
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The edu_check_range function checks that start <= end1 < end2, where
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end1 is the upper bound (exclusive) of the guest-supplied DMA range and
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end2 is the upper bound (exclusive) of the device's allowed DMA range.
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When the guest tries to transfer exactly DMA_SIZE (4096) bytes, end1
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will be equal to end2, so the check fails and QEMU aborts with this
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puzzling error message (newlines added for formatting):
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qemu: hardware error: EDU: DMA range
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0x0000000000040000-0x0000000000040fff out of bounds
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(0x0000000000040000-0x0000000000040fff)!
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By checking end1 <= end2 instead, guests will be allowed to transfer
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exactly 4096 bytes. It is not necessary to explicitly check for
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start <= end1 because the previous two checks (within(addr, start, end2)
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and end1 > addr) imply start < end1.
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Fixes: b30934cb52a7 ("hw: misc, add educational driver", 2015-01-21)
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Signed-off-by: Max Erenberg <merenber@uwaterloo.ca>
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Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
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Signed-off-by: Zhang Jiao <zhangjiao2_yewu@cmss.chinamobile.com>
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---
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hw/misc/edu.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/hw/misc/edu.c b/hw/misc/edu.c
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index a1f8bc77e7..e64a246d3f 100644
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--- a/hw/misc/edu.c
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+++ b/hw/misc/edu.c
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@@ -115,7 +115,7 @@ static void edu_check_range(uint64_t addr, uint64_t size1, uint64_t start,
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uint64_t end2 = start + size2;
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if (within(addr, start, end2) &&
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- end1 > addr && within(end1, start, end2)) {
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+ end1 > addr && end1 <= end2) {
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return;
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}
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--
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2.41.0.windows.1
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