Hi Ales! Thanks for the review. I've addressed requested changes in v2 with your Acked-by added:
https://patchwork.ozlabs.org/project/ovn/patch/20240522121913.609332-1-odiv...@gmail.com/ regards, Vladislav Odintsov On 22.05.2024, 10:59, "dev on behalf of Ales Musil" <ovs-dev-boun...@openvswitch.org on behalf of amu...@redhat.com> wrote: On Tue, May 14, 2024 at 9:25 PM Vladislav Odintsov <odiv...@gmail.com> wrote: > These structure members are read in pinctrl_handler() in a separare thread. > This is unsafe: when IDL is re-connected or some IDL objects are freed > after svc_monitors list with svc_monitor structures, which point to > sbrec_service_monitor is initialized, sb_svc_mon structure property can > point to wrong address, which then leads to segmentation fault in > svc_monitor_send_tcp_health_check__() and > svc_monitor_send_udp_health_check() on accessing svc_mon->sb_svc_mon. > > Imagine situation: > > Main ovn-controller thread: > 1. Connects to SB and fills IDL with DB contents. > 2. run pinctrl_run() with pinctrl mutex and sync_svc_monitors() as a part > of it. > 3. Release mutex. > > ... > 4. Loss of OVNSB connection for any reason (network outage/inactivity probe > timeout/etc), start new main-loop iteration, re-initialize IDL in > ovsdb_idl_run() (which probably will destroy previous IDL objects). > ... > > pinctrl thread: > 5. Awake from poll_block(). > ... run new iteration in its main loop ... > 6. Aqcuire mutex lock. > 7. Run svc_monitors_run(), run svc_monitor_send_tcp_health_check__() or > svc_monitor_send_udp_health_check(), which try to access IDL objects > with outdated pointers. > > 8. Segmentation fault: > > Stack trace of thread 212406: > >> __GI_strlen (libc.so.6) > >> inet_pton (libc.so.6) > >> ip_parse (ovn-controller) > >> svc_monitor_send_tcp_health_check__.part.37 (ovn-controller) > >> svc_monitor_send_health_check (ovn-controller) > >> pinctrl_handler (ovn-controller) > >> ovsthread_wrapper (ovn-controller) > >> start_thread (libpthread.so.0) > >> __clone (libc.so.6) > > This patch removes unsafe access to IDL objects from pinctrl thread. > New svc_monitor structure members are used to store needed data. > > CC: Numan Siddique <num...@ovn.org> > Fixes: 8be01f4a5329 ("Send service monitor health checks") > Signed-off-by: Vladislav Odintsov <odiv...@gmail.com> > --- > Hi Vladislav, thank you for the fix. I have one comment down below. > controller/pinctrl.c | 43 ++++++++++++++++++++++--------------------- > 1 file changed, 22 insertions(+), 21 deletions(-) > > diff --git a/controller/pinctrl.c b/controller/pinctrl.c > index 6a2c3dc68..b843edb35 100644 > --- a/controller/pinctrl.c > +++ b/controller/pinctrl.c > @@ -7307,6 +7307,9 @@ struct svc_monitor { > long long int timestamp; > bool is_ip6; > > + struct eth_addr src_mac; > + struct in6_addr src_ip; > + > long long int wait_time; > long long int next_send_time; > > @@ -7501,6 +7504,15 @@ sync_svc_monitors(struct ovsdb_idl_txn > *ovnsb_idl_txn, > svc_mon->n_success = 0; > svc_mon->n_failures = 0; > > + eth_addr_from_string(sb_svc_mon->src_mac, &svc_mon->src_mac); > + if (is_ipv4) { > + ovs_be32 ip4_src; > + ip_parse(sb_svc_mon->src_ip, &ip4_src); > + svc_mon->src_ip = in6_addr_mapped_ipv4(ip4_src); > + } else { > + ipv6_parse(sb_svc_mon->src_ip, &svc_mon->src_ip); > + } > + > The whole if else block can be replaced with ip46_parse(). hmap_insert(&svc_monitors_map, &svc_mon->hmap_node, hash); > ovs_list_push_back(&svc_monitors, &svc_mon->list_node); > changed = true; > @@ -8259,19 +8271,14 @@ svc_monitor_send_tcp_health_check__(struct rconn > *swconn, > struct dp_packet packet; > dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub); > > - struct eth_addr eth_src; > - eth_addr_from_string(svc_mon->sb_svc_mon->src_mac, ð_src); > if (svc_mon->is_ip6) { > - struct in6_addr ip6_src; > - ipv6_parse(svc_mon->sb_svc_mon->src_ip, &ip6_src); > - pinctrl_compose_ipv6(&packet, eth_src, svc_mon->ea, > - &ip6_src, &svc_mon->ip, IPPROTO_TCP, > + pinctrl_compose_ipv6(&packet, svc_mon->src_mac, svc_mon->ea, > + &svc_mon->src_ip, &svc_mon->ip, IPPROTO_TCP, > 63, TCP_HEADER_LEN); > } else { > - ovs_be32 ip4_src; > - ip_parse(svc_mon->sb_svc_mon->src_ip, &ip4_src); > - pinctrl_compose_ipv4(&packet, eth_src, svc_mon->ea, > - ip4_src, > in6_addr_get_mapped_ipv4(&svc_mon->ip), > + pinctrl_compose_ipv4(&packet, svc_mon->src_mac, svc_mon->ea, > + in6_addr_get_mapped_ipv4(&svc_mon->src_ip), > + in6_addr_get_mapped_ipv4(&svc_mon->ip), > IPPROTO_TCP, 63, TCP_HEADER_LEN); > } > > @@ -8327,24 +8334,18 @@ svc_monitor_send_udp_health_check(struct rconn > *swconn, > struct svc_monitor *svc_mon, > ovs_be16 udp_src) > { > - struct eth_addr eth_src; > - eth_addr_from_string(svc_mon->sb_svc_mon->src_mac, ð_src); > - > uint64_t packet_stub[128 / 8]; > struct dp_packet packet; > dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub); > > if (svc_mon->is_ip6) { > - struct in6_addr ip6_src; > - ipv6_parse(svc_mon->sb_svc_mon->src_ip, &ip6_src); > - pinctrl_compose_ipv6(&packet, eth_src, svc_mon->ea, > - &ip6_src, &svc_mon->ip, IPPROTO_UDP, > + pinctrl_compose_ipv6(&packet, svc_mon->src_mac, svc_mon->ea, > + &svc_mon->src_ip, &svc_mon->ip, IPPROTO_UDP, > 63, UDP_HEADER_LEN + 8); > } else { > - ovs_be32 ip4_src; > - ip_parse(svc_mon->sb_svc_mon->src_ip, &ip4_src); > - pinctrl_compose_ipv4(&packet, eth_src, svc_mon->ea, > - ip4_src, > in6_addr_get_mapped_ipv4(&svc_mon->ip), > + pinctrl_compose_ipv4(&packet, svc_mon->src_mac, svc_mon->ea, > + in6_addr_get_mapped_ipv4(&svc_mon->src_ip), > + in6_addr_get_mapped_ipv4(&svc_mon->ip), > IPPROTO_UDP, 63, UDP_HEADER_LEN + 8); > } > > -- > 2.44.0 > > _______________________________________________ > dev mailing list > d...@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > Other than that it looks good, feel free to add "Acked-by: Ales Musil < amu...@redhat.com>" to v2. Thanks, Ales -- Ales Musil Senior Software Engineer - OVN Core Red Hat EMEA <https://www.redhat.com> amu...@redhat.com <https://red.ht/sig> _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
