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From: BALATON Zoltan <balaton@eik.bme.hu>
To: qemu-devel@nongnu.org
Cc: Gerd Hoffmann <kraxel@redhat.com>
Subject: [PATCH] ati-vga: Do not allow unaligned access via index register
Date: Sat, 16 May 2020 15:13:03 +0200	[thread overview]
Message-ID: <20200516132352.39E9374594E@zero.eik.bme.hu> (raw)

According to docs bits 1 and 0 of MM_INDEX are hard coded to 0 so
unaligned access via this register should not be possible.
This also fixes problems reported in bug #1878134.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
---
 hw/display/ati.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/display/ati.c b/hw/display/ati.c
index f4c4542751..2ee23173b2 100644
--- a/hw/display/ati.c
+++ b/hw/display/ati.c
@@ -531,7 +531,7 @@ static void ati_mm_write(void *opaque, hwaddr addr,
     }
     switch (addr) {
     case MM_INDEX:
-        s->regs.mm_index = data;
+        s->regs.mm_index = data & ~3;
         break;
     case MM_DATA ... MM_DATA + 3:
         /* indexed access to regs or memory */
-- 
2.21.3



             reply	other threads:[~2020-05-16 13:25 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-16 13:13 BALATON Zoltan [this message]
2020-05-16 14:47 ` [PATCH] ati-vga: Do not allow unaligned access via index register Alexander Bulekov
2020-05-16 15:33   ` BALATON Zoltan
2020-05-17 10:40     ` Philippe Mathieu-Daudé
2020-05-17 13:12       ` Philippe Mathieu-Daudé
2020-05-17 14:30         ` BALATON Zoltan
2020-05-17 17:54           ` Philippe Mathieu-Daudé
2020-05-18 13:37           ` Gerd Hoffmann

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