[Qemu-devel] [PATCH] Fix an infinite loop in the emulated SB16 device

[Aurelien Jarno]

This patch from Tavis Ormandy <address@hidden> fixes an infinite
loop in the emulated SB16 device.

See http://taviso.decsystem.org/virtsec.pdf for more details.
---
 hw/sb16.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/sb16.c b/hw/sb16.c
index c22de7a..b2a3a70 100644
--- a/hw/sb16.c
+++ b/hw/sb16.c
@@ -1246,8 +1246,10 @@ static int SB_read_DMA (void *opaque, int nchan, int 
dma_pos, int dma_len)
             s->block_size);
 #endif
 
-    while (s->left_till_irq <= 0) {
-        s->left_till_irq = s->block_size + s->left_till_irq;
+    if (s->block_size) {
+        while (s->left_till_irq <= 0) {
+            s->left_till_irq = s->block_size + s->left_till_irq;
+        }
     }
 
     return dma_pos;

-- 
  .''`.  Aurelien Jarno             | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   address@hidden         | address@hidden
   `-    people.debian.org/~aurel32 | www.aurel32.net