1From f64cfa931a450ffb08cbbdeb6652b424f6bb8187 Mon Sep 17 00:00:00 2001
2From: Michael Forney <mforney@mforney.org>
3Date: Thu, 30 Jan 2020 14:12:35 -0800
4Subject: [PATCH] Avoid use of alloca and statement expressions
5
6---
7 include/netlink-private/utils.h | 21 ---------------------
8 lib/genl/mngt.c | 13 +++++++++----
9 2 files changed, 9 insertions(+), 25 deletions(-)
10
11diff --git a/include/netlink-private/utils.h b/include/netlink-private/utils.h
12index 1456797..e26399f 100644
13--- a/include/netlink-private/utils.h
14+++ b/include/netlink-private/utils.h
15@@ -93,27 +93,6 @@ extern const char *nl_strerror_l(int err);
16
17 /*****************************************************************************/
18
19-#define _nl_malloc_maybe_a(alloca_maxlen, bytes, to_free) \
20- ({ \
21- const size_t _bytes = (bytes); \
22- __typeof__ (to_free) _to_free = (to_free); \
23- __typeof__ (*_to_free) _ptr; \
24- \
25- _NL_STATIC_ASSERT ((alloca_maxlen) <= 500); \
26- _nl_assert (_to_free && !*_to_free); \
27- \
28- if (_bytes <= (alloca_maxlen)) { \
29- _ptr = alloca (_bytes); \
30- } else { \
31- _ptr = malloc (_bytes); \
32- *_to_free = _ptr; \
33- }; \
34- \
35- _ptr; \
36- })
37-
38-/*****************************************************************************/
39-
40 static inline char *
41 _nl_strncpy_trunc(char *dst, const char *src, size_t len)
42 {
43diff --git a/lib/genl/mngt.c b/lib/genl/mngt.c
44index ff50e1d..8f92122 100644
45--- a/lib/genl/mngt.c
46+++ b/lib/genl/mngt.c
47@@ -54,7 +54,7 @@ static int cmd_msg_parser(struct sockaddr_nl *who, struct nlmsghdr *nlh,
48 int err;
49 struct genlmsghdr *ghdr;
50 struct genl_cmd *cmd;
51- struct nlattr **tb;
52+ struct nlattr **tb, *tb_local[32];
53
54 ghdr = genlmsg_hdr(nlh);
55
56@@ -64,9 +64,14 @@ static int cmd_msg_parser(struct sockaddr_nl *who, struct nlmsghdr *nlh,
57 if (cmd->c_msg_parser == NULL)
58 return -NLE_OPNOTSUPP;
59
60- tb = _nl_malloc_maybe_a (300, (((size_t) cmd->c_maxattr) + 1u) * sizeof (struct nlattr *), &tb_free);
61- if (!tb)
62- return -NLE_NOMEM;
63+ if (cmd->c_maxattr > ARRAY_SIZE(tb_local) - 1) {
64+ tb = malloc(((size_t) cmd->c_maxattr + 1u) * sizeof (struct nlattr *));
65+ if (!tb)
66+ return -NLE_NOMEM;
67+ tb_free = tb;
68+ } else {
69+ tb = tb_local;
70+ }
71
72 err = nlmsg_parse(nlh,
73 GENL_HDRSIZE(ops->o_hdrsize),
74--
752.25.0
76
