From cc2d7efc5ca09a7de4bec55e80476986839a655c Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Fri, 14 May 2021 15:58:15 +0900 Subject: [PATCH] network: fix Link reference counter issue Previously, when link_new() fails, `link_unref()` was called, so, `Manager::links` may become dirty. This introduces `link_drop_or_unref()` and it will be called on failure. Upstream-Status: Backport [https://github.com/systemd/systemd-stable/commit/cc2d7efc5ca09a7de4bec55e80476986839a655c] Signed-off-by: Ranjitsinh Rathod --- src/network/networkd-link.c | 240 ++++++++++++++++++------------------ 1 file changed, 122 insertions(+), 118 deletions(-) diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c index b56c232eca..d493afda4c 100644 --- a/src/network/networkd-link.c +++ b/src/network/networkd-link.c @@ -540,109 +540,6 @@ static int link_update_flags(Link *link, return 0; } -static int link_new(Manager *manager, sd_netlink_message *message, Link **ret) { - _cleanup_(link_unrefp) Link *link = NULL; - uint16_t type; - const char *ifname, *kind = NULL; - int r, ifindex; - unsigned short iftype; - - assert(manager); - assert(message); - assert(ret); - - /* check for link kind */ - r = sd_netlink_message_enter_container(message, IFLA_LINKINFO); - if (r == 0) { - (void) sd_netlink_message_read_string(message, IFLA_INFO_KIND, &kind); - r = sd_netlink_message_exit_container(message); - if (r < 0) - return r; - } - - r = sd_netlink_message_get_type(message, &type); - if (r < 0) - return r; - else if (type != RTM_NEWLINK) - return -EINVAL; - - r = sd_rtnl_message_link_get_ifindex(message, &ifindex); - if (r < 0) - return r; - else if (ifindex <= 0) - return -EINVAL; - - r = sd_rtnl_message_link_get_type(message, &iftype); - if (r < 0) - return r; - - r = sd_netlink_message_read_string(message, IFLA_IFNAME, &ifname); - if (r < 0) - return r; - - link = new(Link, 1); - if (!link) - return -ENOMEM; - - *link = (Link) { - .n_ref = 1, - .manager = manager, - .state = LINK_STATE_PENDING, - .ifindex = ifindex, - .iftype = iftype, - - .n_dns = (unsigned) -1, - .dns_default_route = -1, - .llmnr = _RESOLVE_SUPPORT_INVALID, - .mdns = _RESOLVE_SUPPORT_INVALID, - .dnssec_mode = _DNSSEC_MODE_INVALID, - .dns_over_tls_mode = _DNS_OVER_TLS_MODE_INVALID, - }; - - link->ifname = strdup(ifname); - if (!link->ifname) - return -ENOMEM; - - if (kind) { - link->kind = strdup(kind); - if (!link->kind) - return -ENOMEM; - } - - r = sd_netlink_message_read_u32(message, IFLA_MASTER, (uint32_t *)&link->master_ifindex); - if (r < 0) - log_link_debug_errno(link, r, "New device has no master, continuing without"); - - r = sd_netlink_message_read_ether_addr(message, IFLA_ADDRESS, &link->mac); - if (r < 0) - log_link_debug_errno(link, r, "MAC address not found for new device, continuing without"); - - if (asprintf(&link->state_file, "/run/systemd/netif/links/%d", link->ifindex) < 0) - return -ENOMEM; - - if (asprintf(&link->lease_file, "/run/systemd/netif/leases/%d", link->ifindex) < 0) - return -ENOMEM; - - if (asprintf(&link->lldp_file, "/run/systemd/netif/lldp/%d", link->ifindex) < 0) - return -ENOMEM; - - r = hashmap_ensure_allocated(&manager->links, NULL); - if (r < 0) - return r; - - r = hashmap_put(manager->links, INT_TO_PTR(link->ifindex), link); - if (r < 0) - return r; - - r = link_update_flags(link, message, false); - if (r < 0) - return r; - - *ret = TAKE_PTR(link); - - return 0; -} - void link_ntp_settings_clear(Link *link) { link->ntp = strv_free(link->ntp); } @@ -2030,9 +1927,9 @@ static void link_drop_requests(Link *lin request_drop(req); } -void link_drop(Link *link) { +Link *link_drop(Link *link) { if (!link) - return; + return NULL; assert(link->manager); @@ -2057,7 +1954,7 @@ void link_drop(Link *link) { /* The following must be called at last. */ assert_se(hashmap_remove(link->manager->links, INT_TO_PTR(link->ifindex)) == link); - link_unref(link); + return link_unref(link); } static int link_joined(Link *link) { @@ -3295,6 +3192,112 @@ ipv4ll_address_fail: return 0; } + +static Link *link_drop_or_unref(Link *link) { + if (!link) + return NULL; + if (!link->manager) + return link_unref(link); + return link_drop(link); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(Link*, link_drop_or_unref); + +static int link_new(Manager *manager, sd_netlink_message *message, Link **ret) { + _cleanup_(link_drop_or_unrefp) Link *link = NULL; + uint16_t type; + _cleanup_free_ char *ifname = NULL, *kind = NULL; + int r, ifindex; + unsigned short iftype; + + assert(manager); + assert(message); + assert(ret); + + r = sd_netlink_message_get_type(message, &type); + if (r < 0) + return r; + else if (type != RTM_NEWLINK) + return -EINVAL; + + r = sd_rtnl_message_link_get_ifindex(message, &ifindex); + if (r < 0) + return r; + else if (ifindex <= 0) + return -EINVAL; + + r = sd_rtnl_message_link_get_type(message, &iftype); + if (r < 0) + return r; + + r = sd_netlink_message_read_string_strdup(message, IFLA_IFNAME, &ifname); + if (r < 0) + return r; + + /* check for link kind */ + r = sd_netlink_message_enter_container(message, IFLA_LINKINFO); + if (r >= 0) { + (void) sd_netlink_message_read_string_strdup(message, IFLA_INFO_KIND, &kind); + r = sd_netlink_message_exit_container(message); + if (r < 0) + return r; + } + + link = new(Link, 1); + if (!link) + return -ENOMEM; + + *link = (Link) { + .n_ref = 1, + .state = LINK_STATE_PENDING, + .ifindex = ifindex, + .iftype = iftype, + .ifname = TAKE_PTR(ifname), + .kind = TAKE_PTR(kind), + + .n_dns = (unsigned) -1, + .dns_default_route = -1, + .llmnr = _RESOLVE_SUPPORT_INVALID, + .mdns = _RESOLVE_SUPPORT_INVALID, + .dnssec_mode = _DNSSEC_MODE_INVALID, + .dns_over_tls_mode = _DNS_OVER_TLS_MODE_INVALID, + }; + + r = hashmap_ensure_allocated(&manager->links, NULL); + if (r < 0) + return r; + + r = hashmap_put(manager->links, INT_TO_PTR(link->ifindex), link); + if (r < 0) + return r; + + link->manager = manager; + + r = sd_netlink_message_read_u32(message, IFLA_MASTER, (uint32_t*) &link->master_ifindex); + if (r < 0) + log_link_debug_errno(link, r, "New device has no master, continuing without"); + + r = sd_netlink_message_read_ether_addr(message, IFLA_ADDRESS, &link->mac); + if (r < 0) + log_link_debug_errno(link, r, "MAC address not found for new device, continuing without"); + + if (asprintf(&link->state_file, "/run/systemd/netif/links/%d", link->ifindex) < 0) + return -ENOMEM; + + if (asprintf(&link->lease_file, "/run/systemd/netif/leases/%d", link->ifindex) < 0) + return -ENOMEM; + + if (asprintf(&link->lldp_file, "/run/systemd/netif/lldp/%d", link->ifindex) < 0) + return -ENOMEM; + + r = link_update_flags(link, message, false); + if (r < 0) + return r; + + *ret = TAKE_PTR(link); + + return 0; +} int link_add(Manager *m, sd_netlink_message *message, Link **ret) { _cleanup_(sd_device_unrefp) sd_device *device = NULL; --- a/src/network/networkd-link.h 2021-09-02 18:04:16.900542857 +0530 +++ b/src/network/networkd-link.h 2021-09-02 18:18:56.776571563 +0530 @@ -175,7 +175,7 @@ DEFINE_TRIVIAL_DESTRUCTOR(link_netlink_d int link_get(Manager *m, int ifindex, Link **ret); int link_add(Manager *manager, sd_netlink_message *message, Link **ret); -void link_drop(Link *link); +Link *link_drop(Link *link); int link_down(Link *link, link_netlink_message_handler_t callback);