9p: use unsigned integers for nwqid/count
As specification says, all integers in messages are unsigned. Let's fix
behaviour of p9pdu_vreadf()/p9pdu_vwritef() accordingly.
Fix for p9pdu_vreadf() is critical. If server replies with Rwalk, where
nwqid > SHRT_MAX, the value will be interpreted as negative. kmalloc, in
its order, will cast the value to (very big) size_t.
It should never happen in normal situation: we never submit Twalk with
nwname > 16, but malicious or broken server can still produce
problematic Rwalk.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index ab9127e..305e478 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -273,7 +273,7 @@
}
break;
case 'R':{
- int16_t *nwqid = va_arg(ap, int16_t *);
+ uint16_t *nwqid = va_arg(ap, uint16_t *);
struct p9_qid **wqids =
va_arg(ap, struct p9_qid **);
@@ -448,7 +448,7 @@
}
break;
case 'U':{
- int32_t count = va_arg(ap, int32_t);
+ uint32_t count = va_arg(ap, uint32_t);
const char __user *udata =
va_arg(ap, const void __user *);
errcode = p9pdu_writef(pdu, proto_version, "d",
@@ -479,7 +479,7 @@
}
break;
case 'R':{
- int16_t nwqid = va_arg(ap, int);
+ uint16_t nwqid = va_arg(ap, int);
struct p9_qid *wqids =
va_arg(ap, struct p9_qid *);