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| author | Guillaume Nault <g.nault@alphalink.fr> | 2018-11-07 19:28:58 +0100 |
|---|---|---|
| committer | Dmitry Kozlov <xeb@mail.ru> | 2018-11-12 17:00:38 +0300 |
| commit | c3710b6bca55450339bd882207eaf180d5674dab (patch) | |
| tree | 6ed054091e85d1f98d58b9fbaa1edab5c4013f47 | |
| parent | 1c40018e238dc27c9428631cf71633f218bd7824 (diff) | |
| download | accel-ppp-c3710b6bca55450339bd882207eaf180d5674dab.tar.gz accel-ppp-c3710b6bca55450339bd882207eaf180d5674dab.zip | |
ipcp: fix uninitialised memory access when negociating *-NBNS-Address
When handling the EV_WINS event, IPCP assumes that the ->wins1 and
->wins2 fields of the event structure are properly set. But that may
not be the case.
If only one of the MS-Primary-NBNS-Server or MS-Secondary-NBNS-Server
RADIUS attributes was received, then only ->wins1 or ->wins2 is set,
while the other keeps a non initialised value. This uninitialised value
is then copied by ev_wins() and proposed to the peer when negociating
the Primary-NBNS-Address or Secondary-NBNS-Address IPCP options.
That leaks four bytes of the stack to the network and prevents using
the values found in the [wins] section of accel-ppp.conf as fallback.
Fix this by initialising the whole event structure in rad_proc_attrs().
Then, in ev_wins(), we can check if ->wins1 or ->wins2 is properly set
before copying them. That allows to propery fallback to accel-ppp.conf
values when one of the values was not provided by RADIUS.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
| -rw-r--r-- | accel-pppd/ppp/ipcp_opt_wins.c | 12 | ||||
| -rw-r--r-- | accel-pppd/radius/radius.c | 3 |
2 files changed, 9 insertions, 6 deletions
diff --git a/accel-pppd/ppp/ipcp_opt_wins.c b/accel-pppd/ppp/ipcp_opt_wins.c index c9a3bb5..da4dc9b 100644 --- a/accel-pppd/ppp/ipcp_opt_wins.c +++ b/accel-pppd/ppp/ipcp_opt_wins.c @@ -151,11 +151,15 @@ static void ev_wins(struct ev_wins_t *ev) ppp = container_of(ev->ses, typeof(*ppp), ses); - wins_opt = container_of(ipcp_find_option(ppp, &wins1_opt_hnd), typeof(*wins_opt), opt); - wins_opt->addr = ev->wins1; + if (ev->wins1) { + wins_opt = container_of(ipcp_find_option(ppp, &wins1_opt_hnd), typeof(*wins_opt), opt); + wins_opt->addr = ev->wins1; + } - wins_opt = container_of(ipcp_find_option(ppp, &wins2_opt_hnd), typeof(*wins_opt), opt); - wins_opt->addr = ev->wins2; + if (ev->wins2) { + wins_opt = container_of(ipcp_find_option(ppp, &wins2_opt_hnd), typeof(*wins_opt), opt); + wins_opt->addr = ev->wins2; + } } static void load_config(void) diff --git a/accel-pppd/radius/radius.c b/accel-pppd/radius/radius.c index 5e8196d..dd05b83 100644 --- a/accel-pppd/radius/radius.c +++ b/accel-pppd/radius/radius.c @@ -148,14 +148,13 @@ out_err: int rad_proc_attrs(struct rad_req_t *req) { + struct ev_wins_t wins = {}; struct ev_dns_t dns = {}; struct rad_attr_t *attr; struct ipv6db_addr_t *a; - struct ev_wins_t wins; int res = 0; struct radius_pd_t *rpd = req->rpd; - wins.ses = NULL; req->rpd->acct_interim_interval = conf_acct_interim_interval; list_for_each_entry(attr, &req->reply->attrs, entry) { |