Hi,
kubsan: netinet6/nd6.c:948:42: type mismatch: member access within null pointer
of type 'struct in6_ifaddr'
kubsan: netinet6/nd6_nbr.c:640:43: type mismatch: member access within null
pointer of type 'struct in6_ifaddr'
This codes works as ifaddr ia_ifa is the first field of in6_ifaddr.
So the pointers are the same, and one NULL check works for both.
But in ISO C NULL has a type and this is undefined behavior. So
add a second NULL check that the compiler can optimize away. The
resulting assembler is the same.
ok?
bluhm
Index: netinet6/nd6.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/nd6.c,v
retrieving revision 1.236
diff -u -p -r1.236 nd6.c
--- netinet6/nd6.c 7 Nov 2021 19:38:25 -0000 1.236
+++ netinet6/nd6.c 27 Jan 2022 22:20:06 -0000
@@ -792,6 +792,7 @@ nd6_rtrequest(struct ifnet *ifp, int req
struct sockaddr *gate = rt->rt_gateway;
struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
struct ifaddr *ifa;
+ struct in6_ifaddr *ifa6;
if (ISSET(rt->rt_flags, RTF_GATEWAY|RTF_MULTICAST|RTF_MPLS))
return;
@@ -944,8 +945,9 @@ nd6_rtrequest(struct ifnet *ifp, int req
* check if rt_key(rt) is one of my address assigned
* to the interface.
*/
- ifa = &in6ifa_ifpwithaddr(ifp,
- &satosin6(rt_key(rt))->sin6_addr)->ia_ifa;
+ ifa6 = in6ifa_ifpwithaddr(ifp,
+ &satosin6(rt_key(rt))->sin6_addr);
+ ifa = ifa6 ? &ifa6->ia_ifa : NULL;
if (ifa) {
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
Index: netinet6/nd6_nbr.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet6/nd6_nbr.c,v
retrieving revision 1.130
diff -u -p -r1.130 nd6_nbr.c
--- netinet6/nd6_nbr.c 13 Dec 2021 14:30:16 -0000 1.130
+++ netinet6/nd6_nbr.c 27 Jan 2022 22:20:06 -0000
@@ -568,6 +568,7 @@ nd6_na_input(struct mbuf *m, int off, in
char *lladdr = NULL;
int lladdrlen = 0;
struct ifaddr *ifa;
+ struct in6_ifaddr *ifa6;
struct llinfo_nd6 *ln;
struct rtentry *rt = NULL;
struct sockaddr_dl *sdl;
@@ -637,7 +638,8 @@ nd6_na_input(struct mbuf *m, int off, in
lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
}
- ifa = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa;
+ ifa6 = in6ifa_ifpwithaddr(ifp, &taddr6);
+ ifa = ifa6 ? &ifa6->ia_ifa : NULL;
/*
* Target address matches one of my interface address.
Index: arch/amd64/conf/GENERIC
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/arch/amd64/conf/GENERIC,v
retrieving revision 1.510
diff -u -p -r1.510 GENERIC
--- arch/amd64/conf/GENERIC 4 Jan 2022 05:50:43 -0000 1.510
+++ arch/amd64/conf/GENERIC 27 Jan 2022 22:19:55 -0000
@@ -381,23 +381,23 @@ wsmouse* at pms? mux 0
#mmuagp* at pchb? # amd64 mmu agp.
#agp* at mmuagp?
-inteldrm* at pci? # Intel i915, i945 DRM driver
-intagp* at inteldrm?
-agp* at intagp?
-drm0 at inteldrm? primary 1
-drm* at inteldrm?
-wsdisplay0 at inteldrm? primary 1
-wsdisplay* at inteldrm? mux -1
-radeondrm* at pci? # ATI Radeon DRM driver
-drm0 at radeondrm? primary 1
-drm* at radeondrm?
-wsdisplay0 at radeondrm? primary 1
-wsdisplay* at radeondrm? mux -1
-amdgpu* at pci?
-drm0 at amdgpu? primary 1
-drm* at amdgpu?
-wsdisplay0 at amdgpu? primary 1
-wsdisplay* at amdgpu? mux -1
+#inteldrm* at pci? # Intel i915, i945 DRM driver
+#intagp* at inteldrm?
+#agp* at intagp?
+#drm0 at inteldrm? primary 1
+#drm* at inteldrm?
+#wsdisplay0 at inteldrm? primary 1
+#wsdisplay* at inteldrm? mux -1
+#radeondrm* at pci? # ATI Radeon DRM driver
+#drm0 at radeondrm? primary 1
+#drm* at radeondrm?
+#wsdisplay0 at radeondrm? primary 1
+#wsdisplay* at radeondrm? mux -1
+#amdgpu* at pci?
+#drm0 at amdgpu? primary 1
+#drm* at amdgpu?
+#wsdisplay0 at amdgpu? primary 1
+#wsdisplay* at amdgpu? mux -1
pcppi0 at isa?
Index: arch/amd64/conf/GENERIC.MP
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/arch/amd64/conf/GENERIC.MP,v
retrieving revision 1.16
diff -u -p -r1.16 GENERIC.MP
--- arch/amd64/conf/GENERIC.MP 9 Feb 2021 14:06:19 -0000 1.16
+++ arch/amd64/conf/GENERIC.MP 27 Jan 2022 22:19:55 -0000
@@ -5,5 +5,6 @@ include "arch/amd64/conf/GENERIC"
option MULTIPROCESSOR
#option MP_LOCKDEBUG
#option WITNESS
+option KUBSAN
cpu* at mainbus?
