lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAJGXZLi7LedV_MYr==1RsN6goth73Y4txA=neci_QQcwa5Oqvw@mail.gmail.com> Date: Thu, 6 Apr 2023 18:04:35 +0300 From: Aleksey Shumnik <ashumnik9@...il.com> To: Jakub Kicinski <kuba@...nel.org> Cc: netdev@...r.kernel.org, davem@...emloft.net, dsahern@...nel.org, pabeni@...hat.com, edumazet@...gle.com, a@...table.cc, Thomas.Winter@...iedtelesis.co.nz Subject: Re: [BUG] gre interface incorrectly generates link-local addresses Dear maintainers, I remind you that the problem is still relevant. The problem is not only in generating the number of link-local addresses in an amount equal to the number of addresses on all interfaces defined in /etc/network/interfaces before the gre interface. Due to the new method of link-local address generation, the same link-local address may be formed on several gre interfaces, which may lead to errors in the operation of some network services Would you please answer the following questions > Which linux distribution did you use when you found an error with the > lack of link-local address generation on the gre interface? > After fixing the error, only one link-local address is generated? Is this a bug or an expected behavior? On Sat, Mar 25, 2023 at 1:34 AM Jakub Kicinski <kuba@...nel.org> wrote: > > Adding Thomas as well. > > On Fri, 24 Mar 2023 19:35:06 +0300 Aleksey Shumnik wrote: > > Dear Maintainers, > > > > I found that GRE arbitrarily hangs IP addresses from other interfaces > > described in /etc/network/interfaces above itself (from bottom to > > top). Moreover, this error occurs on both ip4gre and ip6gre. > > > > Example of mgre interface: > > > > 13: mgre1@...E: <MULTICAST,NOARP,UP,LOWER_UP> mtu 1400 qdisc noqueue > > state UNKNOWN group default qlen 1000 > > link/gre 0.0.0.0 brd 0.0.0.0 > > inet 10.10.10.100/8 brd 10.255.255.255 scope global mgre1 > > valid_lft forever preferred_lft forever > > inet6 fe80::a0a:a64/64 scope link > > valid_lft forever preferred_lft forever > > inet6 fe80::7f00:1/64 scope host > > valid_lft forever preferred_lft forever > > inet6 fe80::a0:6842/64 scope host > > valid_lft forever preferred_lft forever > > inet6 fe80::c0a8:1264/64 scope host > > valid_lft forever preferred_lft forever > > > > It seems that after the corrections in the following commits > > https://github.com/torvalds/linux/commit/e5dd729460ca8d2da02028dbf264b65be8cd4b5f > > https://github.com/torvalds/linux/commit/30e2291f61f93f7132c060190f8360df52644ec1 > > https://github.com/torvalds/linux/commit/23ca0c2c93406bdb1150659e720bda1cec1fad04 > > > > in function add_v4_addrs() instead of stopping after this check: > > > > if (addr.s6_addr32[3]) { > > add_addr(idev, &addr, plen, scope, IFAPROT_UNSPEC); > > addrconf_prefix_route(&addr, plen, 0, idev->dev, 0, pflags, > > GFP_KERNEL); > > return; > > } > > > > it goes further and in this cycle hangs addresses from all interfaces on the gre > > > > for_each_netdev(net, dev) { > > struct in_device *in_dev = __in_dev_get_rtnl(dev); > > if (in_dev && (dev->flags & IFF_UP)) { > > struct in_ifaddr *ifa; > > int flag = scope; > > in_dev_for_each_ifa_rtnl(ifa, in_dev) { > > addr.s6_addr32[3] = ifa->ifa_local; > > if (ifa->ifa_scope == RT_SCOPE_LINK) > > continue; > > if (ifa->ifa_scope >= RT_SCOPE_HOST) { > > if (idev->dev->flags&IFF_POINTOPOINT) > > continue; > > flag |= IFA_HOST; > > } > > add_addr(idev, &addr, plen, flag, > > IFAPROT_UNSPEC); > > addrconf_prefix_route(&addr, plen, 0, idev->dev, > > 0, pflags, GFP_KERNEL); > > } > > } > > > > Moreover, before switching to Debian 12 kernel version 6.1.15, I used > > Debian 11 on 5.10.140, and there was no error described in the commit > > https://github.com/torvalds/linux/commit/e5dd729460ca8d2da02028dbf264b65be8cd4b5f. > > One link-local address was always generated on the gre interface, > > regardless of whether the destination or the local address of the > > tunnel was specified. > > > > Which linux distribution did you use when you found an error with the > > lack of link-local address generation on the gre interface? > > After fixing the error, only one link-local address is generated? > > I think this is a bug and most likely the problem is in generating > > dev->dev_addr, since link-local is formed from it. > > > > I suggest solving this problem or roll back the code changes made in > > the comments above. >
Powered by blists - more mailing lists