On Wed, Jun 21, 2023 at 12:47:30PM +0300, Dan Carpenter wrote: > The patchset doesn't include the actual interesting changes, just a > bunch of mechanical prep work. > > On Wed, Jun 21, 2023 at 11:09:55AM +0200, Joel Granados wrote: > > diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c > > index a91283d1e5bf..7b717434368c 100644 > > --- a/net/ieee802154/6lowpan/reassembly.c > > +++ b/net/ieee802154/6lowpan/reassembly.c > > @@ -379,7 +379,8 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) > > table[1].extra2 = &ieee802154_lowpan->fqdir->high_thresh; > > table[2].data = &ieee802154_lowpan->fqdir->timeout; > > > > - hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table); > > + hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table, > > + ARRAY_SIZE(lowpan_frags_ns_ctl_table)); > > For example, in lowpan_frags_ns_sysctl_register() the sentinel is > sometimes element zero if the user doesn't have enough permissions. I > would want to ensure that was handled correctly, but that's going to be > done later in a completely different patchset. I'm definitely not going > to remember to check. On reflecting the patch is obviously wrong. It should be pass zero as table_size in that case. See diff at the end. There is a similar bug in neigh_sysctl_register() where we use memset to zero out the whole table. And another in __ip_vs_lblc_init(). I used the smatch cross function database `smdb.py where ctl_table procname | grep '(null)' | grep min-max` to make a list of functions which set procname to zero. Probably we should add a WARN_ON() if procname is zero in the new code which doesn't use sentinels. regards, dan carpenter drivers/char/random.c | proc_do_uuid | (struct ctl_table)->procname | 0 fs/proc/proc_sysctl.c | new_dir | (struct ctl_table)->procname | 48,3906148897379000352 fs/proc/proc_sysctl.c | new_links | (struct ctl_table)->procname | 4096-ptr_max arch/arm64/kernel/fpsimd.c | vec_proc_do_default_vl | (struct ctl_table)->procname | 0 arch/arm64/kernel/armv8_deprecated.c | register_insn_emulation | (struct ctl_table)->procname | 0-u64max kernel/sysctl-test.c | sysctl_test_api_dointvec_null_tbl_data | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_api_dointvec_table_maxlen_unset | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_api_dointvec_table_len_is_zero | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_api_dointvec_table_read_but_position_set | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_dointvec_read_happy_single_positive | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_dointvec_read_happy_single_negative | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_dointvec_write_happy_single_positive | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_dointvec_write_happy_single_negative | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_api_dointvec_write_single_less_int_min | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl-test.c | sysctl_test_api_dointvec_write_single_greater_int_max | (struct ctl_table)->procname | 7612622206476333056 kernel/sysctl.c | proc_do_static_key | (struct ctl_table)->procname | 0 kernel/kexec_core.c | kexec_limit_handler | (struct ctl_table)->procname | 0 kernel/bpf/syscall.c | bpf_stats_handler | (struct ctl_table)->procname | 0 net/core/sysctl_net_core.c | rps_sock_flow_sysctl | (struct ctl_table)->procname | 0 net/core/sysctl_net_core.c | set_default_qdisc | (struct ctl_table)->procname | 0 net/core/neighbour.c | neigh_sysctl_register | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_lblc.c | __ip_vs_lblc_init | (struct ctl_table)->procname | 0-u64max net/netfilter/ipvs/ip_vs_lblcr.c | __ip_vs_lblcr_init | (struct ctl_table)->procname | 0-u64max net/netfilter/ipvs/ip_vs_ctl.c | proc_do_defense_mode | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_ctl.c | proc_do_sync_threshold | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_ctl.c | proc_do_sync_ports | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_ctl.c | ipvs_proc_est_nice | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_ctl.c | ipvs_proc_run_estimation | (struct ctl_table)->procname | 0 net/netfilter/ipvs/ip_vs_ctl.c | ip_vs_control_net_init_sysctl | (struct ctl_table)->procname | 0-u64max net/netfilter/nf_log.c | netfilter_log_sysctl_init | (struct ctl_table)->procname | 0-u64max net/sctp/sysctl.c | proc_sctp_do_hmac_alg | (struct ctl_table)->procname | 0 net/sctp/sysctl.c | proc_sctp_do_rto_min | (struct ctl_table)->procname | 0 net/sctp/sysctl.c | proc_sctp_do_rto_max | (struct ctl_table)->procname | 0 net/sctp/sysctl.c | proc_sctp_do_auth | (struct ctl_table)->procname | 0 net/sctp/sysctl.c | proc_sctp_do_udp_port | (struct ctl_table)->procname | 0 net/sctp/sysctl.c | proc_sctp_do_probe_interval | (struct ctl_table)->procname | 0 net/ipv6/route.c | ipv6_route_sysctl_init | (struct ctl_table)->procname | 0-u64max net/ipv6/addrconf.c | addrconf_sysctl_addr_gen_mode | (struct ctl_table)->procname | 0 net/ieee802154/6lowpan/reassembly.c | lowpan_frags_ns_sysctl_register | (struct ctl_table)->procname | 0-u64max net/xfrm/xfrm_sysctl.c | xfrm_sysctl_init | (struct ctl_table)->procname | 0-u64max net/phonet/sysctl.c | proc_local_port_range | (struct ctl_table)->procname | 0 net/ipv4/route.c | sysctl_route_net_init | (struct ctl_table)->procname | 0-u64max net/ipv4/sysctl_net_ipv4.c | ipv4_local_port_range | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | ipv4_privileged_ports | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | ipv4_ping_group_range | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_tcp_congestion_control | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_tcp_available_congestion_control | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_allowed_congestion_control | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_tcp_fastopen_key | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_tcp_available_ulp | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_tcp_ehash_entries | (struct ctl_table)->procname | 0 net/ipv4/sysctl_net_ipv4.c | proc_udp_hash_entries | (struct ctl_table)->procname | 0 diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c index a91283d1e5bf..749238d38014 100644 --- a/net/ieee802154/6lowpan/reassembly.c +++ b/net/ieee802154/6lowpan/reassembly.c @@ -360,6 +360,7 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) struct ctl_table_header *hdr; struct netns_ieee802154_lowpan *ieee802154_lowpan = net_ieee802154_lowpan(net); + size_t table_size = ARRAY_SIZE(lowpan_frags_ns_ctl_table); table = lowpan_frags_ns_ctl_table; if (!net_eq(net, &init_net)) { @@ -369,8 +370,10 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) goto err_alloc; /* Don't export sysctls to unprivileged users */ - if (net->user_ns != &init_user_ns) + if (net->user_ns != &init_user_ns) { table[0].procname = NULL; + table_size = 0; + } } table[0].data = &ieee802154_lowpan->fqdir->high_thresh; @@ -379,7 +382,7 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) table[1].extra2 = &ieee802154_lowpan->fqdir->high_thresh; table[2].data = &ieee802154_lowpan->fqdir->timeout; - hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table); + hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table, table_size); if (hdr == NULL) goto err_reg;