On 2018-06-25 12:05, Richard Guy Briggs wrote: > On 2018-06-21 16:50, Dan Carpenter wrote: > > Hello Richard Guy Briggs, > > Hi Dan, Hi Dan, > > This is a semi-automatic email about new static checker warnings. > > Thanks for the report. I'll have a closer look when I've got a chance, > but I see the point. I don't know if it is possible off the top of my > head. Ok, having a closer look, git blame from before that patch shows the same logic, so it appears I didn't change whether or not this is a bug. Digging a bit deeper, the original netlink_alloc_groups() was called if nladdr->nl_groups was non-zero to create nlk->groups, and groups is set to nladdr->nl_groups. After the rename, netlink_realloc_groups() creates it regardless, so this looks safe. > > > The patch 4f520900522f: "netlink: have netlink per-protocol bind > > function return an error code." from Apr 22, 2014, leads to the > > following Smatch complaint: > > > > net/netlink/af_netlink.c:1056 netlink_bind() > > error: we previously assumed 'nlk->groups' could be null (see line 1049) > > > > net/netlink/af_netlink.c > > 1048 > > 1049 if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) > > ^^^^^^^ > > > > 1050 goto unlock; > > 1051 netlink_unlock_table(); > > 1052 > > 1053 netlink_table_grab(); > > 1054 netlink_update_subscriptions(sk, nlk->subscriptions + > > 1055 hweight32(groups) - > > 1056 hweight32(nlk->groups[0])); > > ^^^^^^^^^^^^^^ > > Say groups is non-NULL and nlk->groups is NULL then this would be an > > issue. Is that possible? I don't know why Smatch is just now suddenly > > complaining about a 4 year old patch. > > > > 1057 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; > > 1058 netlink_update_listeners(sk); > > > > regards, > > dan carpenter > > - RGB > > -- > Richard Guy Briggs <rgb@xxxxxxxxxx> > Sr. S/W Engineer, Kernel Security, Base Operating Systems > Remote, Ottawa, Red Hat Canada > IRC: rgb, SunRaycer > Voice: +1.647.777.2635, Internal: (81) 32635 - RGB -- Richard Guy Briggs <rgb@xxxxxxxxxx> Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
