RFC8981 section 3.4 says that existing temporary addresses must have their lifetimes adjusted so that no temporary addresses should ever remain "valid" or "preferred" longer than the incoming SLAAC Prefix Information. This would strongly imply in Linux's case that if the "mngtmpaddr" address is deleted or un-flagged as such, its corresponding temporary addresses must be cleared out right away.

But now the temporary address is renewed even after ‘mngtmpaddr’ is removed or becomes unmanaged as manage_tempaddrs() set temporary addresses prefered/valid time to 0, and later in addrconf_verify_rtnl() all checkings failed to remove the addresses. Fix this by deleting the temporary address directly for these situations.

Fixes: 778964f2fdf0 ("ipv6/addrconf: fix timing bug in tempaddr regen") Signed-off-by: Hangbin Liu liuhangbin@gmail.com --- net/ipv6/addrconf.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 94dceac52884..01115e1a34cb 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2570,6 +2570,24 @@ static struct inet6_dev *addrconf_add_dev(struct net_device *dev) return idev; }

+static void delete_tempaddrs(struct inet6_dev *idev, + struct inet6_ifaddr *ifp) +{ + struct inet6_ifaddr *ift, *tmp; + + write_lock_bh(&idev->lock); + list_for_each_entry_safe(ift, tmp, &idev->tempaddr_list, tmp_list) { + if (ift->ifpub != ifp) + continue; + + in6_ifa_hold(ift); + write_unlock_bh(&idev->lock); + ipv6_del_addr(ift); + write_lock_bh(&idev->lock); + } + write_unlock_bh(&idev->lock); +} + static void manage_tempaddrs(struct inet6_dev *idev, struct inet6_ifaddr *ifp, __u32 valid_lft, __u32 prefered_lft, @@ -3124,11 +3142,12 @@ static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags, in6_ifa_hold(ifp); read_unlock_bh(&idev->lock);

- if (!(ifp->flags & IFA_F_TEMPORARY) && - (ifa_flags & IFA_F_MANAGETEMPADDR)) - manage_tempaddrs(idev, ifp, 0, 0, false, - jiffies); ipv6_del_addr(ifp); + + if (!(ifp->flags & IFA_F_TEMPORARY) && + (ifp->flags & IFA_F_MANAGETEMPADDR)) + delete_tempaddrs(idev, ifp); + addrconf_verify_rtnl(net); if (ipv6_addr_is_multicast(pfx)) { ipv6_mc_config(net->ipv6.mc_autojoin_sk, @@ -4952,14 +4971,12 @@ static int inet6_addr_modify(struct net *net, struct inet6_ifaddr *ifp, }

if (was_managetempaddr || ifp->flags & IFA_F_MANAGETEMPADDR) { - if (was_managetempaddr && - !(ifp->flags & IFA_F_MANAGETEMPADDR)) { - cfg->valid_lft = 0; - cfg->preferred_lft = 0; - } - manage_tempaddrs(ifp->idev, ifp, cfg->valid_lft, - cfg->preferred_lft, !was_managetempaddr, - jiffies); + if (was_managetempaddr && !(ifp->flags & IFA_F_MANAGETEMPADDR)) + delete_tempaddrs(ifp->idev, ifp); + else + manage_tempaddrs(ifp->idev, ifp, cfg->valid_lft, + cfg->preferred_lft, !was_managetempaddr, + jiffies); }

addrconf_verify_rtnl(net);

Add a test to check the temporary address could be added/removed correctly when mngtempaddr is set or removed/unmanaged.

Signed-off-by: Sam Edwards cfsworks@gmail.com Signed-off-by: Hangbin Liu liuhangbin@gmail.com --- tools/testing/selftests/net/rtnetlink.sh | 95 ++++++++++++++++++++++++ 1 file changed, 95 insertions(+)

diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh index bdf6f10d0558..b63053202524 100755 --- a/tools/testing/selftests/net/rtnetlink.sh +++ b/tools/testing/selftests/net/rtnetlink.sh @@ -29,6 +29,7 @@ ALL_TESTS=" kci_test_bridge_parent_id kci_test_address_proto kci_test_enslave_bonding + kci_test_mngtmpaddr "

devdummy="test-dummy0" @@ -44,6 +45,7 @@ check_err() if [ $ret -eq 0 ]; then ret=$1 fi + [ -n "$2" ] && echo "$2" }

# same but inverted -- used when command must fail for test to pass @@ -1267,6 +1269,99 @@ kci_test_enslave_bonding() ip netns del "$testns" }

+# Called to validate the addresses on $IFNAME: +# +# 1. Every `temporary` address must have a matching `mngtmpaddr` +# 2. Every `mngtmpaddr` address must have some un`deprecated` `temporary` +# +# If the mngtmpaddr or tempaddr checking failed, return 0 and stop slowwait +validate_mngtmpaddr() +{ + local dev=$1 + local prefix="" + local addr_list=$(ip -j -n $testns addr show dev ${dev}) + local temp_addrs=$(echo ${addr_list} | \ + jq -r '.[].addr_info[] | select(.temporary == true) | .local') + local mng_prefixes=$(echo ${addr_list} | \ + jq -r '.[].addr_info[] | select(.mngtmpaddr == true) | .local' | \ + cut -d: -f1-4 | tr '\n' ' ') + local undep_prefixes=$(echo ${addr_list} | \ + jq -r '.[].addr_info[] | select(.temporary == true and .deprecated != true) | .local' | \ + cut -d: -f1-4 | tr '\n' ' ') + + # 1. All temporary addresses (temp and dep) must have a matching mngtmpaddr + for address in ${temp_addrs}; do + prefix=$(echo ${address} | cut -d: -f1-4) + if [[ ! " ${mng_prefixes} " =~ " $prefix " ]]; then + check_err 1 "FAIL: Temporary $address with no matching mngtmpaddr!"; + return 0 + fi + done + + # 2. All mngtmpaddr addresses must have a temporary address (not dep) + for prefix in ${mng_prefixes}; do + if [[ ! " ${undep_prefixes} " =~ " $prefix " ]]; then + check_err 1 "FAIL: No undeprecated temporary in $prefix!"; + return 0 + fi + done + + return 1 +} + +kci_test_mngtmpaddr() +{ + local ret=0 + + setup_ns testns + if [ $? -ne 0 ]; then + end_test "SKIP mngtmpaddr tests: cannot add net namespace $testns" + return $ksft_skip + fi + + # 1. Create a dummy Ethernet interface + run_cmd ip -n $testns link add ${devdummy} type dummy + run_cmd ip -n $testns link set ${devdummy} up + run_cmd ip netns exec $testns sysctl -w net.ipv6.conf.${devdummy}.use_tempaddr=1 + run_cmd ip netns exec $testns sysctl -w net.ipv6.conf.${devdummy}.temp_prefered_lft=10 + run_cmd ip netns exec $testns sysctl -w net.ipv6.conf.${devdummy}.temp_valid_lft=25 + run_cmd ip netns exec $testns sysctl -w net.ipv6.conf.${devdummy}.max_desync_factor=1 + + # 2. Create several mngtmpaddr addresses on that interface. + # with temp_*_lft configured to be pretty short (10 and 35 seconds + # for prefer/valid respectively) + for i in $(seq 1 9); do + run_cmd ip -n $testns addr add 2001:db8:7e57:${i}::1/64 mngtmpaddr dev ${devdummy} + done + + # 3. Confirm that a preferred temporary address exists for each mngtmpaddr + # address at all times, polling once per second for 30 seconds. + slowwait 30 validate_mngtmpaddr ${devdummy} + + # 4. Delete each mngtmpaddr address, one at a time (alternating between + # deleting and merely un-mngtmpaddr-ing), and confirm that the other + # mngtmpaddr addresses still have preferred temporaries. + for i in $(seq 1 9); do + (( $i % 4 == 0 )) && mng_flag="mngtmpaddr" || mng_flag="" + if (( $i % 2 == 0 )); then + run_cmd ip -n $testns addr del 2001:db8:7e57:${i}::1/64 $mng_flag dev ${devdummy} + else + run_cmd ip -n $testns addr change 2001:db8:7e57:${i}::1/64 dev ${devdummy} + fi + # the temp addr should be deleted + validate_mngtmpaddr ${devdummy} + done + + if [ $ret -ne 0 ]; then + end_test "FAIL: mngtmpaddr add/remove incorrect" + else + end_test "PASS: mngtmpaddr add/remove correctly" + fi + + ip netns del "$testns" + return $ret +} + kci_test_rtnl() { local current_test