kernel/linux.git/net/ipv6/addrconf.c, branch v5.18

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-03-03T19:55:12+00:00

net/batman-adv/hard-interface.c commit 690bb6fb64f5 ("batman-adv: Request iflink once in batadv-on-batadv check") commit 6ee3c393eeb7 ("batman-adv: Demote batadv-on-batadv skip error message") https://lore.kernel.org/all/20220302163049.101957-1-sw@simonwunderlich.de/ net/smc/af_smc.c commit 4d08b7b57ece ("net/smc: Fix cleanup when register ULP fails") commit 462791bbfa35 ("net/smc: add sysctl interface for SMC") https://lore.kernel.org/all/20220302112209.355def40@canb.auug.org.au/ Signed-off-by: Jakub Kicinski

net: ipv6: ensure we call ipv6_mc_down() at most once

2022-02-28T11:04:45+00:00

There are two reasons for addrconf_notify() to be called with NETDEV_DOWN: either the network device is actually going down, or IPv6 was disabled on the interface. If either of them stays down while the other is toggled, we repeatedly call the code for NETDEV_DOWN, including ipv6_mc_down(), while never calling the corresponding ipv6_mc_up() in between. This will cause a new entry in idev->mc_tomb to be allocated for each multicast group the interface is subscribed to, which in turn leaks one struct ifmcaddr6 per nontrivial multicast group the interface is subscribed to. The following reproducer will leak at least $n objects: ip addr add ff2e::4242/32 dev eth0 autojoin sysctl -w net.ipv6.conf.eth0.disable_ipv6=1 for i in $(seq 1 $n); do ip link set up eth0; ip link set down eth0 done Joining groups with IPV6_ADD_MEMBERSHIP (unprivileged) or setting the sysctl net.ipv6.conf.eth0.forwarding to 1 (=> subscribing to ff02::2) can also be used to create a nontrivial idev->mc_list, which will the leak objects with the right up-down-sequence. Based on both sources for NETDEV_DOWN events the interface IPv6 state should be considered: - not ready if the network interface is not ready OR IPv6 is disabled for it - ready if the network interface is ready AND IPv6 is enabled for it The functions ipv6_mc_up() and ipv6_down() should only be run when this state changes. Implement this by remembering when the IPv6 state is ready, and only run ipv6_mc_down() if it actually changed from ready to not ready. The other direction (not ready -> ready) already works correctly, as: - the interface notification triggered codepath for NETDEV_UP / NETDEV_CHANGE returns early if ipv6 is disabled, and - the disable_ipv6=0 triggered codepath skips fully initializing the interface as long as addrconf_link_ready(dev) returns false - calling ipv6_mc_up() repeatedly does not leak anything Fixes: 3ce62a84d53c ("ipv6: exit early in addrconf_notify() if IPv6 is disabled") Signed-off-by: Johannes Nixdorf Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-02-25T01:54:25+00:00

tools/testing/selftests/net/mptcp/mptcp_join.sh 34aa6e3bccd8 ("selftests: mptcp: add ip mptcp wrappers") 857898eb4b28 ("selftests: mptcp: add missing join check") 6ef84b1517e0 ("selftests: mptcp: more robust signal race test") https://lore.kernel.org/all/20220221131842.468893-1-broonie@kernel.org/ drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/act.h drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/ct.c fb7e76ea3f3b6 ("net/mlx5e: TC, Skip redundant ct clear actions") c63741b426e11 ("net/mlx5e: Fix MPLSoUDP encap to use MPLS action information") 09bf97923224f ("net/mlx5e: TC, Move pedit_headers_action to parse_attr") 84ba8062e383 ("net/mlx5e: Test CT and SAMPLE on flow attr") efe6f961cd2e ("net/mlx5e: CT, Don't set flow flag CT for ct clear flow") 3b49a7edec1d ("net/mlx5e: TC, Reject rules with multiple CT actions") Signed-off-by: Jakub Kicinski

ipv6: prevent a possible race condition with lifetimes

2022-02-24T17:10:23+00:00

valid_lft, prefered_lft and tstamp are always accessed under the lock "lock" in other places. Reading these without taking the lock may result in inconsistencies regarding the calculation of the valid and preferred variables since decisions are taken on these fields for those variables. Signed-off-by: Niels Dossche Reviewed-by: David Ahern Signed-off-by: Niels Dossche Link: https://lore.kernel.org/r/20220223131954.6570-1-niels.dossche@ugent.be Signed-off-by: Jakub Kicinski

net: Add new protocol attribute to IP addresses

2022-02-19T05:20:06+00:00

This patch adds a new protocol attribute to IPv4 and IPv6 addresses. Inspiration was taken from the protocol attribute of routes. User space applications like iproute2 can set/get the protocol with the Netlink API. The attribute is stored as an 8-bit unsigned integer. The protocol attribute is set by kernel for these categories: - IPv4 and IPv6 loopback addresses - IPv6 addresses generated from router announcements - IPv6 link local addresses User space may pass custom protocols, not defined by the kernel. Grouping addresses on their origin is useful in scenarios where you want to distinguish between addresses based on who added them, e.g. kernel vs. user space. Tagging addresses with a string label is an existing feature that could be used as a solution. Unfortunately the max length of a label is 15 characters, and for compatibility reasons the label must be prefixed with the name of the device followed by a colon. Since device names also have a max length of 15 characters, only -1 characters is guaranteed to be available for any origin tag, which is not that much. A reference implementation of user space setting and getting protocols is available for iproute2: https://github.com/westermo/iproute2/commit/9a6ea18bd79f47f293e5edc7780f315ea42ff540 Signed-off-by: Jacques de Laval Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-02-17T19:44:20+00:00

No conflicts. Signed-off-by: Jakub Kicinski

ipv6/addrconf: ensure addrconf_verify_rtnl() has completed

2022-02-17T16:41:54+00:00

Before freeing the hash table in addrconf_exit_net(), we need to make sure the work queue has completed, or risk NULL dereference or UAF. Thus, use cancel_delayed_work_sync() to enforce this. We do not hold RTNL in addrconf_exit_net(), making this safe. Fixes: 8805d13ff1b2 ("ipv6/addrconf: use one delayed work per netns") Signed-off-by: Eric Dumazet Reported-by: syzbot Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220216182037.3742-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

ipv6: blackhole_netdev needs snmp6 counters

2022-02-14T14:04:27+00:00

Whenever rt6_uncached_list_flush_dev() swaps rt->rt6_idev to the blackhole device, parts of IPv6 stack might still need to increment one SNMP counter. Root cause, patch from Ido, changelog from Eric :) This bug suggests that we need to audit rt->rt6_idev usages and make sure they are properly using RCU protection. Fixes: e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev") Signed-off-by: Ido Schimmel Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

ipv6: mcast: use rcu-safe version of ipv6_get_lladdr()

2022-02-14T13:30:37+00:00

Some time ago 8965779d2c0e ("ipv6,mcast: always hold idev->lock before mca_lock") switched ipv6_get_lladdr() to __ipv6_get_lladdr(), which is rcu-unsafe version. That was OK, because idev->lock was held for these codepaths. In 88e2ca308094 ("mld: convert ifmcaddr6 to RCU") these external locks were removed, so we probably need to restore the original rcu-safe call. Otherwise, we occasionally get a machine crashed/stalled with the following in dmesg: [ 3405.966610][T230589] general protection fault, probably for non-canonical address 0xdead00000000008c: 0000 [#1] SMP NOPTI [ 3405.982083][T230589] CPU: 44 PID: 230589 Comm: kworker/44:3 Tainted: G O 5.15.19-cloudflare-2022.2.1 #1 [ 3405.998061][T230589] Hardware name: SUPA-COOL-SERV [ 3406.009552][T230589] Workqueue: mld mld_ifc_work [ 3406.017224][T230589] RIP: 0010:__ipv6_get_lladdr+0x34/0x60 [ 3406.025780][T230589] Code: 57 10 48 83 c7 08 48 89 e5 48 39 d7 74 3e 48 8d 82 38 ff ff ff eb 13 48 8b 90 d0 00 00 00 48 8d 82 38 ff ff ff 48 39 d7 74 22 <66> 83 78 32 20 77 1b 75 e4 89 ca 23 50 2c 75 dd 48 8b 50 08 48 8b [ 3406.055748][T230589] RSP: 0018:ffff94e4b3fc3d10 EFLAGS: 00010202 [ 3406.065617][T230589] RAX: dead00000000005a RBX: ffff94e4b3fc3d30 RCX: 0000000000000040 [ 3406.077477][T230589] RDX: dead000000000122 RSI: ffff94e4b3fc3d30 RDI: ffff8c3a31431008 [ 3406.089389][T230589] RBP: ffff94e4b3fc3d10 R08: 0000000000000000 R09: 0000000000000000 [ 3406.101445][T230589] R10: ffff8c3a31430000 R11: 000000000000000b R12: ffff8c2c37887100 [ 3406.113553][T230589] R13: ffff8c3a39537000 R14: 00000000000005dc R15: ffff8c3a31431000 [ 3406.125730][T230589] FS: 0000000000000000(0000) GS:ffff8c3b9fc80000(0000) knlGS:0000000000000000 [ 3406.138992][T230589] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3406.149895][T230589] CR2: 00007f0dfea1db60 CR3: 000000387b5f2000 CR4: 0000000000350ee0 [ 3406.162421][T230589] Call Trace: [ 3406.170235][T230589] [ 3406.177736][T230589] mld_newpack+0xfe/0x1a0 [ 3406.186686][T230589] add_grhead+0x87/0xa0 [ 3406.195498][T230589] add_grec+0x485/0x4e0 [ 3406.204310][T230589] ? newidle_balance+0x126/0x3f0 [ 3406.214024][T230589] mld_ifc_work+0x15d/0x450 [ 3406.223279][T230589] process_one_work+0x1e6/0x380 [ 3406.232982][T230589] worker_thread+0x50/0x3a0 [ 3406.242371][T230589] ? rescuer_thread+0x360/0x360 [ 3406.252175][T230589] kthread+0x127/0x150 [ 3406.261197][T230589] ? set_kthread_struct+0x40/0x40 [ 3406.271287][T230589] ret_from_fork+0x22/0x30 [ 3406.280812][T230589] [ 3406.288937][T230589] Modules linked in: ... [last unloaded: kheaders] [ 3406.476714][T230589] ---[ end trace 3525a7655f2f3b9e ]--- Fixes: 88e2ca308094 ("mld: convert ifmcaddr6 to RCU") Reported-by: David Pinilla Caparros Signed-off-by: Ignat Korchagin Signed-off-by: David S. Miller

ipv6: give an IPv6 dev to blackhole_netdev

2022-02-11T11:44:27+00:00

IPv6 addrconf notifiers wants the loopback device to be the last device being dismantled at netns deletion. This caused many limitations and work arounds. Back in linux-5.3, Mahesh added a per host blackhole_netdev that can be used whenever we need to make sure objects no longer refer to a disappearing device. If we attach to blackhole_netdev an ip6_ptr (allocate an idev), then we can use this special device (which is never freed) in place of the loopback_dev (which can be freed). This will permit improvements in netdev_run_todo() and other parts of the stack where had steps to make sure loopback_dev was the last device to disappear. Signed-off-by: Eric Dumazet Cc: Mahesh Bandewar Signed-off-by: David S. Miller