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[PATCH] ati-vga: increment mm_index in ati_mm_read/write
From: |
P J P |
Subject: |
[PATCH] ati-vga: increment mm_index in ati_mm_read/write |
Date: |
Wed, 3 Jun 2020 18:17:32 +0530 |
From: Prasad J Pandit <pjp@fedoraproject.org>
While accessing VGA registers via ati_mm_read/write routines,
a guest may set 's->regs.mm_index' such that it leads to infinite
recursion. Increment the mm_index value to avoid it.
Reported-by: Ren Ding <rding@gatech.edu>
Reported-by: Hanqing Zhao <hanqing@gatech.edu>
Reported-by: Yi Ren <c4tren@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
hw/display/ati.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/hw/display/ati.c b/hw/display/ati.c
index 065f197678..fa9061ad0b 100644
--- a/hw/display/ati.c
+++ b/hw/display/ati.c
@@ -286,7 +286,8 @@ static uint64_t ati_mm_read(void *opaque, hwaddr addr,
unsigned int size)
val = ldn_le_p(s->vga.vram_ptr + idx, size);
}
} else {
- val = ati_mm_read(s, s->regs.mm_index + addr - MM_DATA, size);
+ uint32_t idx = s->regs.mm_index++;
+ val = ati_mm_read(s, idx + addr - MM_DATA, size);
}
break;
case BIOS_0_SCRATCH ... BUS_CNTL - 1:
@@ -521,7 +522,8 @@ static void ati_mm_write(void *opaque, hwaddr addr,
stn_le_p(s->vga.vram_ptr + idx, size, data);
}
} else {
- ati_mm_write(s, s->regs.mm_index + addr - MM_DATA, data, size);
+ uint32_t idx = s->regs.mm_index++;
+ ati_mm_write(s, idx + addr - MM_DATA, data, size);
}
break;
case BIOS_0_SCRATCH ... BUS_CNTL - 1:
--
2.26.2
- [PATCH] ati-vga: increment mm_index in ati_mm_read/write,
P J P <=