matthias
/
iproute2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

iplink: check for message truncation in iplink_get() 

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>
This commit is contained in:
Michal Kubecek 2017-09-01 18:39:11 +02:00 committed by Stephen Hemminger
parent bc4a57b879
commit 6599162b95
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
ip/iplink.c
View File

@ -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);