[Qemu-devel] [PATCH] hw/9pfs: Fix segfault with 9p2000.u

[Aneesh Kumar K.V]

From: "Aneesh Kumar K.V" <address@hidden>

When guest tries to chmod a block or char device file over 9pfs,
the qemu process segfaults. With 9p2000.u protocol we use wstat to
change mode bits and client don't send extension information for
chmod. We need to check for size field to check whether extension
info is present or not.

Signed-off-by: Aneesh Kumar K.V <address@hidden>
---
 hw/9pfs/virtio-9p.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 296f66f..8cbb8ae 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -658,7 +658,7 @@ static mode_t v9mode_to_mode(uint32_t mode, V9fsString 
*extension)
         ret |= S_IFIFO;
     }
     if (mode & P9_STAT_MODE_DEVICE) {
-        if (extension && extension->data[0] == 'c') {
+        if (extension->size && extension->data[0] == 'c') {
             ret |= S_IFCHR;
         } else {
             ret |= S_IFBLK;
-- 
1.8.1.2