On Thu, Jun 29, 2017 at 06:22:40PM +0200, Pablo Neira Ayuso wrote: > On Tue, Jun 27, 2017 at 07:05:27PM +0200, Pablo Neira Ayuso wrote: > > On Tue, Jun 27, 2017 at 05:58:25PM +0200, Pablo Neira Ayuso wrote: > > > On Wed, Jun 07, 2017 at 03:50:38PM +0200, Mateusz Jurczyk wrote: > > > > Verify that the length of the socket buffer is sufficient to cover the > > > > nlmsghdr structure before accessing the nlh->nlmsg_len field for further > > > > input sanitization. If the client only supplies 1-3 bytes of data in > > > > sk_buff, then nlh->nlmsg_len remains partially uninitialized and > > > > contains leftover memory from the corresponding kernel allocation. > > > > Operating on such data may result in indeterminate evaluation of the > > > > nlmsg_len < NLMSG_HDRLEN expression. > > > > > > > > The bug was discovered by a runtime instrumentation designed to detect > > > > use of uninitialized memory in the kernel. The patch prevents this and > > > > other similar tools (e.g. KMSAN) from flagging this behavior in the future. > > > > > > Applied, thanks. > > > > Wait, I keeping this back after closer look. > > > > I think we have to remove this: > > > > if (nlh->nlmsg_len < NLMSG_HDRLEN || <--- > > skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) > > return; > > > > in nfnetlink_rcv_skb_batch() > > > > now that we make this unfront check from nfnetlink_rcv(). > > BTW, I can just mangle your patch here to delete such line to speed up > things. See the mangled patch that is attached to this email. OK, I have applied this to the nf tree. Thanks! -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
