Add a check for a NULL mbuf ptr at the beginning of xdrmbuf_inline()

so that it returns failure instead of crashing when "m->m_len" is
executed and m == NULL. The mbuf ptr can be NULL when a call to
xdrmbuf_getbytes() gets the bytes it needs, but they are at the end
of a short RPC reply. When this happens, xdrmbuf_getbytes() returns
success, but advances the mbuf ptr (xdrs->x_private) to m_next, which
is NULL. If this is followed by a call to xdrmbuf_getlong(), it calls
xdrmbuf_inline(), which would cause a crash by accessing "m->m_len".

Tested by:	pho, serenity at exscape dot org
Approved by:	re (rwatson), kib (mentor)
This commit is contained in:
Rick Macklem 2009-08-12 16:27:51 +00:00
parent 8b28fd0239
commit 0990c0a12c

View File

@ -282,6 +282,8 @@ xdrmbuf_inline(XDR *xdrs, u_int len)
size_t available;
char *p;
if (!m)
return (0);
if (xdrs->x_op == XDR_ENCODE) {
available = M_TRAILINGSPACE(m) + (m->m_len - xdrs->x_handy);
} else {