ip: fix crash in "ip neigh show"

parse_rtattr() was using tb[] array without initializing it.

Based on patch by Balaji Punnuru <balaji_punnuru@cable.comcast.com>

function                                             old     new   delta
parse_rtattr                                          85     107     +22
print_route                                         1630    1617     -13
print_linkinfo                                       807     794     -13
iproute_get                                          835     822     -13
print_rule                                           680     665     -15
ll_remember_index                                    263     248     -15
print_addrinfo                                      1223    1197     -26
ipaddr_list_or_flush                                1253    1223     -30
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/7 up/down: 22/-125)          Total: -103 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 9 deletions

diff --git a/networking/tc.c b/networking/tc.c
index 23abf636c..284c93098 100644
--- a/networking/tc.c
+++ b/networking/tc.c
@@ -57,17 +57,21 @@
 
 /* nullifies tb on error */
 #define __parse_rtattr_nested_compat(tb, max, rta, len) \
-        ({if ((RTA_PAYLOAD(rta) >= len) && \
-                 (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr))) { \
-                        rta = RTA_DATA(rta) + RTA_ALIGN(len); \
-                        parse_rtattr_nested(tb, max, rta); \
-          } else \
-                        memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); \
-        })
+({ \
+        if ((RTA_PAYLOAD(rta) >= len) \
+         && (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) \
+        ) { \
+                rta = RTA_DATA(rta) + RTA_ALIGN(len); \
+                parse_rtattr_nested(tb, max, rta); \
+        } else \
+                memset(tb, 0, sizeof(struct rtattr *) * (max + 1)); \
+})
 
 #define parse_rtattr_nested_compat(tb, max, rta, data, len) \
-        ({data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL; \
-        __parse_rtattr_nested_compat(tb, max, rta, len); })
+({ \
+        data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL; \
+        __parse_rtattr_nested_compat(tb, max, rta, len); \
+})
 
 #define show_details (0) /* not implemented. Does anyone need it? */
 #define use_iec (0) /* not currently documented in the upstream manpage */