When parsing and printing the unix sockets in unix_show(), if the oldformat is detected, the peer_name member of the sockstat object is left uninitialized (NULL). For this reason, if a filter has been specified on the command line, a strcmp() will crash when trying to access it.
Avoid crash by checking that peer_name is not NULL before passing it to strcmp(). Cc: Stefano Brivio <sbri...@redhat.com> Cc: Stephen Hemminger <step...@networkplumber.org> Signed-off-by: Antonio Quartulli <a...@unstable.cc> --- To crash ss, simply execute the following on a system using the old socket format: ss -x dst 192.168.1.1 or ss dst 192.168.1.1 (crash reproduced on linux-4.12.12) misc/ss.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/misc/ss.c b/misc/ss.c index b35859dc..29a25070 100644 --- a/misc/ss.c +++ b/misc/ss.c @@ -3711,7 +3711,10 @@ static int unix_show(struct filter *f) }; memcpy(st.local.data, &u->name, sizeof(u->name)); - if (strcmp(u->peer_name, "*")) + /* when parsing the old format rport is set to 0 and + * therefore peer_name remains NULL + */ + if (u->peer_name && strcmp(u->peer_name, "*")) memcpy(st.remote.data, &u->peer_name, sizeof(u->peer_name)); if (run_ssfilter(f->f, &st) == 0) { -- 2.15.1