kernel.git/net/ipv6/addrconf.c, branch linux-6.5.y

net: release reference to inet6_dev pointer

2023-10-10T20:02:55Z

commit 5cb249686e67dbef3ffe53887fa725eefc5a7144 upstream. addrconf_prefix_rcv returned early without releasing the inet6_dev pointer when the PIO lifetime is less than accept_ra_min_lft. Fixes: 5027d54a9c30 ("net: change accept_ra_min_rtr_lft to affect all RA lifetimes") Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Cc: David Ahern Cc: Simon Horman Reviewed-by: Simon Horman Reviewed-by: Maciej Żenczykowski Signed-off-by: Patrick Rohr Reviewed-by: Leon Romanovsky Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: change accept_ra_min_rtr_lft to affect all RA lifetimes

2023-10-10T20:02:55Z

commit 5027d54a9c30bc7ec808360378e2b4753f053f25 upstream. accept_ra_min_rtr_lft only considered the lifetime of the default route and discarded entire RAs accordingly. This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and applies the value to individual RA sections; in particular, router lifetime, PIO preferred lifetime, and RIO lifetime. If any of those lifetimes are lower than the configured value, the specific RA section is ignored. In order for the sysctl to be useful to Android, it should really apply to all lifetimes in the RA, since that is what determines the minimum frequency at which RAs must be processed by the kernel. Android uses hardware offloads to drop RAs for a fraction of the minimum of all lifetimes present in the RA (some networks have very frequent RAs (5s) with high lifetimes (2h)). Despite this, we have encountered networks that set the router lifetime to 30s which results in very frequent CPU wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the WiFi firmware) entirely on such networks, it seems better to ignore the misconfigured routers while still processing RAs from other IPv6 routers on the same network (i.e. to support IoT applications). The previous implementation dropped the entire RA based on router lifetime. This turned out to be hard to expand to the other lifetimes present in the RA in a consistent manner; dropping the entire RA based on RIO/PIO lifetimes would essentially require parsing the whole thing twice. Fixes: 1671bcfd76fd ("net: add sysctl accept_ra_min_rtr_lft") Cc: Lorenzo Colitti Signed-off-by: Patrick Rohr Reviewed-by: Maciej Żenczykowski Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: add sysctl accept_ra_min_rtr_lft

2023-10-10T20:02:55Z

commit 1671bcfd76fdc0b9e65153cf759153083755fe4c upstream. This change adds a new sysctl accept_ra_min_rtr_lft to specify the minimum acceptable router lifetime in an RA. If the received RA router lifetime is less than the configured value (and not 0), the RA is ignored. This is useful for mobile devices, whose battery life can be impacted by networks that configure RAs with a short lifetime. On such networks, the device should never gain IPv6 provisioning and should attempt to drop RAs via hardware offload, if available. Signed-off-by: Patrick Rohr Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: ipv6/addrconf: avoid integer underflow in ipv6_create_tempaddr

2023-09-19T10:30:18Z

[ Upstream commit f31867d0d9d82af757c1e0178b659438f4c1ea3c ] The existing code incorrectly casted a negative value (the result of a subtraction) to an unsigned value without checking. For example, if /proc/sys/net/ipv6/conf/*/temp_prefered_lft was set to 1, the preferred lifetime would jump to 4 billion seconds. On my machine and network the shortest lifetime that avoided underflow was 3 seconds. Fixes: 76506a986dc3 ("IPv6: fix DESYNC_FACTOR") Signed-off-by: Alex Henrie Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

ipv6 addrconf: fix bug where deleting a mngtmpaddr can create a new temporary address

2023-07-24T22:51:21Z

currently on 6.4 net/main: # ip link add dummy1 type dummy # echo 1 > /proc/sys/net/ipv6/conf/dummy1/use_tempaddr # ip link set dummy1 up # ip -6 addr add 2000::1/64 mngtmpaddr dev dummy1 # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::44f3:581c:8ca:3983/64 scope global temporary dynamic valid_lft 604800sec preferred_lft 86172sec inet6 2000::1/64 scope global mngtmpaddr valid_lft forever preferred_lft forever inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever # ip -6 addr del 2000::44f3:581c:8ca:3983/64 dev dummy1 (can wait a few seconds if you want to, the above delete isn't [directly] the problem) # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::1/64 scope global mngtmpaddr valid_lft forever preferred_lft forever inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever # ip -6 addr del 2000::1/64 mngtmpaddr dev dummy1 # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::81c9:56b7:f51a:b98f/64 scope global temporary dynamic valid_lft 604797sec preferred_lft 86169sec inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever This patch prevents this new 'global temporary dynamic' address from being created by the deletion of the related (same subnet prefix) 'mngtmpaddr' (which is triggered by there already being no temporary addresses). Cc: Jiri Pirko Fixes: 53bd67491537 ("ipv6 addrconf: introduce IFA_F_MANAGETEMPADDR to tell kernel to manage temporary addresses") Reported-by: Xiao Ma Signed-off-by: Maciej Żenczykowski Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230720160022.1887942-1-maze@google.com Signed-off-by: Jakub Kicinski

ipv6/addrconf: fix a potential refcount underflow for idev

2023-07-09T10:19:01Z

Now in addrconf_mod_rs_timer(), reference idev depends on whether rs_timer is not pending. Then modify rs_timer timeout. There is a time gap in [1], during which if the pending rs_timer becomes not pending. It will miss to hold idev, but the rs_timer is activated. Thus rs_timer callback function addrconf_rs_timer() will be executed and put idev later without holding idev. A refcount underflow issue for idev can be caused by this. if (!timer_pending(&idev->rs_timer)) in6_dev_hold(idev); <--------------[1] mod_timer(&idev->rs_timer, jiffies + when); To fix the issue, hold idev if mod_timer() return 0. Fixes: b7b1bfce0bb6 ("ipv6: split duplicate address detection and router solicitation timer") Suggested-by: Eric Dumazet Signed-off-by: Ziyang Xuan Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: lower "link become ready"'s level message

2023-06-04T14:39:10Z

This following message is printed in the console each time a network device configured with an IPv6 addresses is ready to be used: ADDRCONF(NETDEV_CHANGE): : link becomes ready When netns are being extensively used -- e.g. by re-creating netns' with veth to discuss with each others for testing purposes like mptcp_join.sh selftest does -- it generates a lot of messages like that: more than 700 when executing mptcp_join.sh with the latest version. It looks like this message is not that helpful after all: maybe it can be used as a sign to know if there is something wrong, e.g. if a device is being regularly reconfigured by accident? But even then, there are better ways to monitor and diagnose such issues. When looking at commit 3c21edbd1137 ("[IPV6]: Defer IPv6 device initialization until the link becomes ready.") which introduces this new message, it seems it had been added to verify that the new feature was working as expected. It could have then used a lower level than "info" from the beginning but it was fine like that back then: 17 years ago. It seems then OK today to simply lower its level, similar to commit 7c62b8dd5ca8 ("net/ipv6: lower the level of "link is not ready" messages") and as suggested by Mat [1], Stephen and David [2]. Link: https://lore.kernel.org/mptcp/614e76ac-184e-c553-af72-084f792e60b0@kernel.org/T/ [1] Link: https://lore.kernel.org/netdev/68035bad-b53e-91cb-0e4a-007f27d62b05@tessares.net/T/ [2] Suggested-by: Mat Martineau Suggested-by: Stephen Hemminger Suggested-by: David Ahern Signed-off-by: Matthieu Baerts Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: prevent router_solicitations for team port

2023-03-24T08:57:06Z

The issue fixed for bonding in commit c2edacf80e15 ("bonding / ipv6: no addrconf for slaves separately from master") also exists in team driver. However, we can't just disable ipv6 addrconf for team ports, as 'teamd' will need it when nsns_ping watch is used in the user space. Instead of preventing ipv6 addrconf, this patch only prevents RS packets for team ports, as it did in commit b52e1cce31ca ("ipv6: Don't send rs packets to the interface of ARPHRD_TUNNEL"). Note that we do not prevent DAD packets, to avoid the changes getting intricate / hacky. Also, usually sysctl dad_transmits is set to 1 and only 1 DAD packet will be sent, and by now no libteam user complains about DAD packets on team ports, unlike RS packets. Signed-off-by: Xin Long Reviewed-by: Simon Horman Signed-off-by: David S. Miller

neighbour: switch to standard rcu, instead of rcu_bh

2023-03-22T04:32:18Z

rcu_bh is no longer a win, especially for objects freed with standard call_rcu(). Switch neighbour code to no longer disable BH when not necessary. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

ip/ip6_gre: Fix non-point-to-point tunnel not generating IPv6 link local address

2023-02-02T03:52:22Z

We recently found that our non-point-to-point tunnels were not generating any IPv6 link local address and instead generating an IPv6 compat address, breaking IPv6 communication on the tunnel. Previously, addrconf_gre_config always would call addrconf_addr_gen and generate a EUI64 link local address for the tunnel. Then commit e5dd729460ca changed the code path so that add_v4_addrs is called but this only generates a compat IPv6 address for non-point-to-point tunnels. I assume the compat address is specifically for SIT tunnels so have kept that only for SIT - GRE tunnels now always generate link local addresses. Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address") Signed-off-by: Thomas Winter Signed-off-by: Jakub Kicinski