| Message ID | b54be39a6f4688613fba5f0b7a1dcad245149b20.1504283683.git.mkubecek@suse.cz |
|---|---|
| State | Accepted, archived |
| Delegated to: | stephen hemminger |
| Headers | show |
| Series | fix "ip link show dev ..." for NICs with many VFs | expand |
diff --git a/ip/iplink.c b/ip/iplink.c index 5aff2fde38da..790e3a138bb0 100644 --- a/ip/iplink.c +++ b/ip/iplink.c @@ -1040,6 +1040,11 @@ int iplink_get(unsigned int flags, char *name, __u32 filt_mask) if (rtnl_talk(&rth, &req.n, &answer.n, sizeof(answer)) < 0) return -2; + if (answer.n.nlmsg_len > sizeof(answer.buf)) { + fprintf(stderr, "Message truncated from %u to %lu\n", + answer.n.nlmsg_len, sizeof(answer.buf)); + return -2; + } if (brief) print_linkinfo_brief(NULL, &answer.n, stdout, NULL);
If message length exceeds maxlen argument of rtnl_talk(), it is truncated to maxlen but unlike in the case of truncation to the length of local buffer in rtnl_talk(), the caller doesn't get any indication of a problem. In particular, iplink_get() passes the truncated message on and parsing it results in various warnings and sometimes even a segfault (observed with "ip link show dev ..." for a NIC with 125 VFs). Handle message truncation in iplink_get() the same way as truncation in rtnl_talk() would be handled: return an error. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> --- ip/iplink.c | 5 +++++ 1 file changed, 5 insertions(+)