[PATCH iproute2] libnetlink: Fix extack attribute parsing
From: David Ahern <hidden>
Date: 2017-08-17 20:43:09
Initialize tb in nl_dump_ext_err since not all attributes will be sent in the messages. Add error checking on mnl_attr_parse and print messages on the off chance the ext ack attributes fail to validate. Signed-off-by: David Ahern <redacted> --- lib/libnetlink.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 81a344abff27..874e660be7eb 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c@@ -49,13 +49,17 @@ static int err_attr_cb(const struct nlattr *attr, void *data) const struct nlattr **tb = data; uint16_t type; - if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) + if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) { + fprintf(stderr, "Invalid extack attribute\n"); return MNL_CB_ERROR; + } type = mnl_attr_get_type(attr); - if (mnl_attr_validate(attr, extack_policy[type]) < 0) + if (mnl_attr_validate(attr, extack_policy[type]) < 0) { + fprintf(stderr, "extack attribute %d failed validation\n", + type); return MNL_CB_ERROR; - + } tb[type] = attr; return MNL_CB_OK;
@@ -64,7 +68,7 @@ static int err_attr_cb(const struct nlattr *attr, void *data) /* dump netlink extended ack error message */ static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn) { - struct nlattr *tb[NLMSGERR_ATTR_MAX + 1]; + struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {}; const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh); const struct nlmsghdr *err_nlh = NULL; unsigned int hlen = sizeof(*err);
@@ -79,7 +83,8 @@ static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn) if (!(nlh->nlmsg_flags & NLM_F_CAPPED)) hlen += mnl_nlmsg_get_payload_len(&err->msg); - mnl_attr_parse(nlh, hlen, err_attr_cb, tb); + if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK) + return 0; if (tb[NLMSGERR_ATTR_MSG]) errmsg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
--
2.1.4