[Qemu-devel] [PATCH] pc: restrict port92 register value to 2 bits

[P J P]

From: Prasad J Pandit <address@hidden>

Port 92 configuration register holds an 8-bit value. Of 8-bits,
bits 0-1 are used and 2-7 are reserved. Restrict the supplied
value to 2 bits.

Reported-by: Niu Guoxiang <address@hidden>
Signed-off-by: Prasad J Pandit <address@hidden>
---
 hw/i386/pc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 05985d4927..883384a599 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -515,6 +515,7 @@ static void port92_write(void *opaque, hwaddr addr, 
uint64_t val,
     Port92State *s = opaque;
     int oldval = s->outport;
 
+    val &= 0x03;
     DPRINTF("port92: write 0x%02" PRIx64 "\n", val);
     s->outport = val;
     qemu_set_irq(s->a20_out, (val >> 1) & 1);
-- 
2.13.6