esp: cancel current request only if some request is in flight

This bug was introduced in 94d3f98a3f3caddd7875f9a11776daeb84962a7b:
scsi_cancel_io was checking if some request was pending before trying
to cancel it, while scsi_req_cancel always cancels the request.

This may lead to a crash of Qemu due to dereferencing a NULL pointer,
as exhibited by NetBSD 5.1 installer on MIPS Magnum emulation.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

diff --git a/hw/esp.c b/hw/esp.c
index 8e95672f0ee0367cc1c75aa2ef6990bdc7739c34..aa50800a56dd0e864473301574aba5b565539c4b 100644 (file)
--- a/hw/esp.c
+++ b/hw/esp.c
@@ -219,7 +219,7 @@ static uint32_t get_cmd(ESPState *s, uint8_t *buf)
     s->ti_rptr = 0;
     s->ti_wptr = 0;
 
-    if (s->current_dev) {
+    if (s->current_req) {
         /* Started a new command before the old one finished.  Cancel it.  */
         scsi_req_cancel(s->current_req);
         s->async_len = 0;