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path: root/include/net/neighbour.h
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2023-11-28neighbour: Fix __randomize_layout crash in struct neighbourGustavo A. R. Silva
Previously, one-element and zero-length arrays were treated as true flexible arrays, even though they are actually "fake" flex arrays. The __randomize_layout would leave them untouched at the end of the struct, similarly to proper C99 flex-array members. However, this approach changed with commit 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays"). Now, only C99 flexible-array members will remain untouched at the end of the struct, while one-element and zero-length arrays will be subject to randomization. Fix a `__randomize_layout` crash in `struct neighbour` by transforming zero-length array `primary_key` into a proper C99 flexible-array member. Fixes: 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays") Closes: https://lore.kernel.org/linux-hardening/20231124102458.GB1503258@e124191.cambridge.arm.com/ Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Joey Gouly <joey.gouly@arm.com> Link: https://lore.kernel.org/r/ZWJoRsJGnCPdJ3+2@work Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-01neighbour: fix data-races around n->outputEric Dumazet
n->output field can be read locklessly, while a writer might change the pointer concurrently. Add missing annotations to prevent load-store tearing. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-07neighbour: Remove unused function declaration pneigh_for_each()Yue Haibing
pneigh_for_each() is never implemented since the beginning of git history. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-01neighbour: fix unaligned access to pneigh_entryQingfang DENG
After the blamed commit, the member key is longer 4-byte aligned. On platforms that do not support unaligned access, e.g., MIPS32R2 with unaligned_action set to 1, this will trigger a crash when accessing an IPv6 pneigh_entry, as the key is cast to an in6_addr pointer. Change the type of the key to u32 to make it aligned. Fixes: 62dd93181aaa ("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.") Signed-off-by: Qingfang DENG <qingfang.deng@siflower.com.cn> Link: https://lore.kernel.org/r/20230601015432.159066-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-21neighbour: switch to standard rcu, instead of rcu_bhEric Dumazet
rcu_bh is no longer a win, especially for objects freed with standard call_rcu(). Switch neighbour code to no longer disable BH when not necessary. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-15neighbour: annotate lockless accesses to n->nud_stateEric Dumazet
We have many lockless accesses to n->nud_state. Before adding another one in the following patch, add annotations to readers and writers. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-09neighbour: delete neigh_lookup_nodev as not usedLeon Romanovsky
neigh_lookup_nodev isn't used in the kernel after removal of DECnet. So let's remove it. Fixes: 1202cdd66531 ("Remove DECnet support from kernel") Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/eb5656200d7964b2d177a36b77efa3c597d6d72d.1678267343.git.leonro@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-11-18net: neigh: decrement the family specific qlenThomas Zeitlhofer
Commit 0ff4eb3d5ebb ("neighbour: make proxy_queue.qlen limit per-device") introduced the length counter qlen in struct neigh_parms. There are separate neigh_parms instances for IPv4/ARP and IPv6/ND, and while the family specific qlen is incremented in pneigh_enqueue(), the mentioned commit decrements always the IPv4/ARP specific qlen, regardless of the currently processed family, in pneigh_queue_purge() and neigh_proxy_process(). As a result, with IPv6/ND, the family specific qlen is only incremented (and never decremented) until it exceeds PROXY_QLEN, and then, according to the check in pneigh_enqueue(), neighbor solicitations are not answered anymore. As an example, this is noted when using the subnet-router anycast address to access a Linux router. After a certain amount of time (in the observed case, qlen exceeded PROXY_QLEN after two days), the Linux router stops answering neighbor solicitations for its subnet-router anycast address and effectively becomes unreachable. Another result with IPv6/ND is that the IPv4/ARP specific qlen is decremented more often than incremented. This leads to negative qlen values, as a signed integer has been used for the length counter qlen, and potentially to an integer overflow. Fix this by introducing the helper function neigh_parms_qlen_dec(), which decrements the family specific qlen. Thereby, make use of the existing helper function neigh_get_dev_parms_rcu(), whose definition therefore needs to be placed earlier in neighbour.c. Take the family member from struct neigh_table to determine the currently processed family and appropriately call neigh_parms_qlen_dec() from pneigh_queue_purge() and neigh_proxy_process(). Additionally, use an unsigned integer for the length counter qlen. Fixes: 0ff4eb3d5ebb ("neighbour: make proxy_queue.qlen limit per-device") Signed-off-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-26neighbour: Remove unused inline function neigh_key_eq16()Gaosheng Cui
All uses of neigh_key_eq16() have been removed since commit 1202cdd66531 ("Remove DECnet support from kernel"), so remove it. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-15neighbour: make proxy_queue.qlen limit per-deviceAlexander Mikhalitsyn
Right now we have a neigh_param PROXY_QLEN which specifies maximum length of neigh_table->proxy_queue. But in fact, this limitation doesn't work well because check condition looks like: tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN) The problem is that p (struct neigh_parms) is a per-device thing, but tbl (struct neigh_table) is a system-wide global thing. It seems reasonable to make proxy_queue limit per-device based. v2: - nothing changed in this patch v3: - rebase to net tree Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Ahern <dsahern@kernel.org> Cc: Yajun Deng <yajun.deng@linux.dev> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Christian Brauner <brauner@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: Konstantin Khorenko <khorenko@virtuozzo.com> Cc: kernel@openvz.org Cc: devel@openvz.org Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-30net, neigh: introduce interval_probe_time_ms for periodic probeYuwei Wang
commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming") fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the system work queue hog CPU to 100%, and further more we should introduce a new option used by periodic probe Signed-off-by: Yuwei Wang <wangyuweihx@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-02-02net, neigh: Do not trigger immediate probes on NUD_FAILED from ↵Daniel Borkmann
neigh_managed_work syzkaller was able to trigger a deadlock for NTF_MANAGED entries [0]: kworker/0:16/14617 is trying to acquire lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 [...] but task is already holding lock: ffffffff8d4dd370 (&tbl->lock){++-.}-{2:2}, at: neigh_managed_work+0x35/0x250 net/core/neighbour.c:1572 The neighbor entry turned to NUD_FAILED state, where __neigh_event_send() triggered an immediate probe as per commit cd28ca0a3dd1 ("neigh: reduce arp latency") via neigh_probe() given table lock was held. One option to fix this situation is to defer the neigh_probe() back to the neigh_timer_handler() similarly as pre cd28ca0a3dd1. For the case of NTF_MANAGED, this deferral is acceptable given this only happens on actual failure state and regular / expected state is NUD_VALID with the entry already present. The fix adds a parameter to __neigh_event_send() in order to communicate whether immediate probe is allowed or disallowed. Existing call-sites of neigh_event_send() default as-is to immediate probe. However, the neigh_managed_work() disables it via use of neigh_event_send_probe(). [0] <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline] check_deadlock kernel/locking/lockdep.c:2999 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __raw_write_lock_bh include/linux/rwlock_api_smp.h:202 [inline] _raw_write_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:334 ___neigh_create+0x9e1/0x2990 net/core/neighbour.c:652 ip6_finish_output2+0x1070/0x14f0 net/ipv6/ip6_output.c:123 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0xa99/0x17f0 net/ipv6/ndisc.c:508 ndisc_send_ns+0x3a9/0x840 net/ipv6/ndisc.c:650 ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:742 neigh_probe+0xc2/0x110 net/core/neighbour.c:1040 __neigh_event_send+0x37d/0x1570 net/core/neighbour.c:1201 neigh_event_send include/net/neighbour.h:470 [inline] neigh_managed_work+0x162/0x250 net/core/neighbour.c:1574 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Fixes: 7482e3841d52 ("net, neigh: Add NTF_MANAGED flag for managed neighbor entries") Reported-by: syzbot+5239d0e1778a500d477a@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Roopa Prabhu <roopa@nvidia.com> Tested-by: syzbot+5239d0e1778a500d477a@syzkaller.appspotmail.com Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20220201193942.5055-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-06net: add net device refcount tracker to struct neigh_parmsEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-06net: add net device refcount tracker to struct pneigh_entryEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-06net: add net device refcount tracker to struct neighbourEric Dumazet
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-23neigh: introduce neigh_confirm() helper functionYajun Deng
Add neigh_confirm() for the confirmed member in struct neighbour, it can be called as an independent unit by other functions. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-26net: annotate data-race in neigh_output()Eric Dumazet
neigh_output() reads n->nud_state and hh->hh_len locklessly. This is fine, but we need to add annotations and document this. We evaluate skip_cache first to avoid reading these fields if the cache has to by bypassed. syzbot report: BUG: KCSAN: data-race in __neigh_event_send / ip_finish_output2 write to 0xffff88810798a885 of 1 bytes by interrupt on cpu 1: __neigh_event_send+0x40d/0xac0 net/core/neighbour.c:1128 neigh_event_send include/net/neighbour.h:444 [inline] neigh_resolve_output+0x104/0x410 net/core/neighbour.c:1476 neigh_output include/net/neighbour.h:510 [inline] ip_finish_output2+0x80a/0xaa0 net/ipv4/ip_output.c:221 ip_finish_output+0x3b5/0x510 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:423 dst_output include/net/dst.h:450 [inline] ip_local_out+0x164/0x220 net/ipv4/ip_output.c:126 __ip_queue_xmit+0x9d3/0xa20 net/ipv4/ip_output.c:525 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:539 __tcp_transmit_skb+0x142a/0x1a00 net/ipv4/tcp_output.c:1405 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline] tcp_xmit_probe_skb net/ipv4/tcp_output.c:4011 [inline] tcp_write_wakeup+0x4a9/0x810 net/ipv4/tcp_output.c:4064 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4079 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x394/0x520 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1421 expire_timers+0x135/0x240 kernel/time/timer.c:1466 __run_timers+0x368/0x430 kernel/time/timer.c:1734 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1747 __do_softirq+0x12c/0x26e kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu kernel/softirq.c:636 [inline] irq_exit_rcu+0x4e/0xa0 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline] acpi_idle_enter+0x258/0x2e0 drivers/acpi/processor_idle.c:688 cpuidle_enter_state+0x2b4/0x760 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x1a3/0x250 kernel/sched/idle.c:306 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403 secondary_startup_64_no_verify+0xb1/0xbb read to 0xffff88810798a885 of 1 bytes by interrupt on cpu 0: neigh_output include/net/neighbour.h:507 [inline] ip_finish_output2+0x79a/0xaa0 net/ipv4/ip_output.c:221 ip_finish_output+0x3b5/0x510 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:423 dst_output include/net/dst.h:450 [inline] ip_local_out+0x164/0x220 net/ipv4/ip_output.c:126 __ip_queue_xmit+0x9d3/0xa20 net/ipv4/ip_output.c:525 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:539 __tcp_transmit_skb+0x142a/0x1a00 net/ipv4/tcp_output.c:1405 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline] tcp_xmit_probe_skb net/ipv4/tcp_output.c:4011 [inline] tcp_write_wakeup+0x4a9/0x810 net/ipv4/tcp_output.c:4064 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4079 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline] tcp_write_timer_handler+0x394/0x520 net/ipv4/tcp_timer.c:626 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1421 expire_timers+0x135/0x240 kernel/time/timer.c:1466 __run_timers+0x368/0x430 kernel/time/timer.c:1734 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1747 __do_softirq+0x12c/0x26e kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu kernel/softirq.c:636 [inline] irq_exit_rcu+0x4e/0xa0 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline] acpi_idle_enter+0x258/0x2e0 drivers/acpi/processor_idle.c:688 cpuidle_enter_state+0x2b4/0x760 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x1a3/0x250 kernel/sched/idle.c:306 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403 rest_init+0xee/0x100 init/main.c:734 arch_call_rest_init+0xa/0xb start_kernel+0x5e4/0x669 init/main.c:1142 secondary_startup_64_no_verify+0xb1/0xbb value changed: 0x20 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-12net, neigh: Add NTF_MANAGED flag for managed neighbor entriesDaniel Borkmann
Allow a user space control plane to insert entries with a new NTF_EXT_MANAGED flag. The flag then indicates to the kernel that the neighbor entry should be periodically probed for keeping the entry in NUD_REACHABLE state iff possible. The use case for this is targeting XDP or tc BPF load-balancers which use the bpf_fib_lookup() BPF helper in order to piggyback on neighbor resolution for their backends. Given they cannot be resolved in fast-path, a control plane inserts the L3 (without L2) entries manually into the neighbor table and lets the kernel do the neighbor resolution either on the gateway or on the backend directly in case the latter resides in the same L2. This avoids to deal with L2 in the control plane and to rebuild what the kernel already does best anyway. NTF_EXT_MANAGED can be combined with NTF_EXT_LEARNED in order to avoid GC eviction. The kernel then adds NTF_MANAGED flagged entries to a per-neighbor table which gets triggered by the system work queue to periodically call neigh_event_send() for performing the resolution. The implementation allows migration from/to NTF_MANAGED neighbor entries, so that already existing entries can be converted by the control plane if needed. Potentially, we could make the interval for periodically calling neigh_event_send() configurable; right now it's set to DELAY_PROBE_TIME which is also in line with mlxsw which has similar driver-internal infrastructure c723c735fa6b ("mlxsw: spectrum_router: Periodically update the kernel's neigh table"). In future, the latter could possibly reuse the NTF_MANAGED neighbors as well. Example: # ./ip/ip n replace 192.168.178.30 dev enp5s0 managed extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a managed extern_learn REACHABLE [...] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Roopa Prabhu <roopa@nvidia.com> Link: https://linuxplumbersconf.org/event/11/contributions/953/ Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-12net, neigh: Extend neigh->flags to 32 bit to allow for extensionsRoopa Prabhu
Currently, all bits in struct ndmsg's ndm_flags are used up with the most recent addition of 435f2e7cc0b7 ("net: bridge: add support for sticky fdb entries"). This makes it impossible to extend the neighboring subsystem with new NTF_* flags: struct ndmsg { __u8 ndm_family; __u8 ndm_pad1; __u16 ndm_pad2; __s32 ndm_ifindex; __u16 ndm_state; __u8 ndm_flags; __u8 ndm_type; }; There are ndm_pad{1,2} attributes which are not used. However, due to uncareful design, the kernel does not enforce them to be zero upon new neighbor entry addition, and given they've been around forever, it is not possible to reuse them today due to risk of breakage. One option to overcome this limitation is to add a new NDA_FLAGS_EXT attribute for extended flags. In struct neighbour, there is a 3 byte hole between protocol and ha_lock, which allows neigh->flags to be extended from 8 to 32 bits while still being on the same cacheline as before. This also allows for all future NTF_* flags being in neigh->flags rather than yet another flags field. Unknown flags in NDA_FLAGS_EXT will be rejected by the kernel. Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Roopa Prabhu <roopa@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-12net, neigh: Enable state migration between NUD_PERMANENT and NTF_USEDaniel Borkmann
Currently, it is not possible to migrate a neighbor entry between NUD_PERMANENT state and NTF_USE flag with a dynamic NUD state from a user space control plane. Similarly, it is not possible to add/remove NTF_EXT_LEARNED flag from an existing neighbor entry in combination with NTF_USE flag. This is due to the latter directly calling into neigh_event_send() without any meta data updates as happening in __neigh_update(). Thus, to enable this use case, extend the latter with a NEIGH_UPDATE_F_USE flag where we break the NUD_PERMANENT state in particular so that a latter neigh_event_send() is able to re-resolve a neighbor entry. Before fix, NUD_PERMANENT -> NUD_* & NTF_USE: # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT [...] As can be seen, despite the admin-triggered replace, the entry remains in the NUD_PERMANENT state. After fix, NUD_PERMANENT -> NUD_* & NTF_USE: # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE [...] # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn STALE [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a PERMANENT [...] After the fix, the admin-triggered replace switches to a dynamic state from the NTF_USE flag which triggered a new neighbor resolution. Likewise, we can transition back from there, if needed, into NUD_PERMANENT. Similar before/after behavior can be observed for below transitions: Before fix, NTF_USE -> NTF_USE | NTF_EXT_LEARNED -> NTF_USE: # ./ip/ip n replace 192.168.178.30 dev enp5s0 use # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE [...] After fix, NTF_USE -> NTF_USE | NTF_EXT_LEARNED -> NTF_USE: # ./ip/ip n replace 192.168.178.30 dev enp5s0 use # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE [...] # ./ip/ip n replace 192.168.178.30 dev enp5s0 use # ./ip/ip n 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE [..] Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Roopa Prabhu <roopa@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-11-13net: Exempt multicast addresses from five-second neighbor lifetimeJeff Dike
Commit 58956317c8de ("neighbor: Improve garbage collection") guarantees neighbour table entries a five-second lifetime. Processes which make heavy use of multicast can fill the neighour table with multicast addresses in five seconds. At that point, neighbour entries can't be GC-ed because they aren't five seconds old yet, the kernel log starts to fill up with "neighbor table overflow!" messages, and sends start to fail. This patch allows multicast addresses to be thrown out before they've lived out their five seconds. This makes room for non-multicast addresses and makes messages to all addresses more reliable in these circumstances. Fixes: 58956317c8de ("neighbor: Improve garbage collection") Signed-off-by: Jeff Dike <jdike@akamai.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20201113015815.31397-1-jdike@akamai.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-06-08net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*Christoph Hellwig
Remove the leftover __user annotation on the prototypes for neigh_proc_dointvec*. The implementations already got this right, but the headers kept the __user tags around. Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler") Reported-by: build test robot <lkp@intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-02-29neighbour: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09neighbour: remove neigh_cleanup() methodEric Dumazet
neigh_cleanup() has not been used for seven years, and was a wrong design. Messing with shared pointer in bond_neigh_init() without proper memory barriers would at least trigger syzbot complains eventually. It is time to remove this stuff. Fixes: b63b70d87741 ("IPoIB: Use a private hash table for path lookup in xmit path") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
One conflict in the BPF samples Makefile, some fixes in 'net' whilst we were converting over to Makefile.target rules in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08net: fix data-race in neigh_event_send()Eric Dumazet
KCSAN reported the following data-race [1] The fix will also prevent the compiler from optimizing out the condition. [1] BUG: KCSAN: data-race in neigh_resolve_output / neigh_resolve_output write to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 1: neigh_event_send include/net/neighbour.h:443 [inline] neigh_resolve_output+0x78/0x480 net/core/neighbour.c:1474 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0xdf/0x210 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532 ip_queue_xmit+0x45/0x60 include/net/ip.h:237 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline] __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598 tcp_write_timer+0xd1/0xf0 net/ipv4/tcp_timer.c:618 read to 0xffff8880a41dba78 of 8 bytes by interrupt on cpu 0: neigh_event_send include/net/neighbour.h:442 [inline] neigh_resolve_output+0x57/0x480 net/core/neighbour.c:1474 neigh_output include/net/neighbour.h:511 [inline] ip_finish_output2+0x4af/0xe40 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x23a/0x490 net/ipv4/ip_output.c:290 ip_finish_output+0x41/0x160 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0xdf/0x210 net/ipv4/ip_output.c:432 dst_output include/net/dst.h:436 [inline] ip_local_out+0x74/0x90 net/ipv4/ip_output.c:125 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532 ip_queue_xmit+0x45/0x60 include/net/ip.h:237 __tcp_transmit_skb+0xe81/0x1d60 net/ipv4/tcp_output.c:1169 tcp_transmit_skb net/ipv4/tcp_output.c:1185 [inline] __tcp_retransmit_skb+0x4bd/0x15f0 net/ipv4/tcp_output.c:2976 tcp_retransmit_skb+0x36/0x1a0 net/ipv4/tcp_output.c:2999 tcp_retransmit_timer+0x719/0x16d0 net/ipv4/tcp_timer.c:515 tcp_write_timer_handler+0x42d/0x510 net/ipv4/tcp_timer.c:598 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-07net: add annotations on hh->hh_len lockless accessesEric Dumazet
KCSAN reported a data-race [1] While we can use READ_ONCE() on the read sides, we need to make sure hh->hh_len is written last. [1] BUG: KCSAN: data-race in eth_header_cache / neigh_resolve_output write to 0xffff8880b9dedcb8 of 4 bytes by task 29760 on cpu 0: eth_header_cache+0xa9/0xd0 net/ethernet/eth.c:247 neigh_hh_init net/core/neighbour.c:1463 [inline] neigh_resolve_output net/core/neighbour.c:1480 [inline] neigh_resolve_output+0x415/0x470 net/core/neighbour.c:1470 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 read to 0xffff8880b9dedcb8 of 4 bytes by task 29572 on cpu 1: neigh_resolve_output net/core/neighbour.c:1479 [inline] neigh_resolve_output+0x113/0x470 net/core/neighbour.c:1470 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505 ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647 rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 29572 Comm: kworker/1:4 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events rt6_probe_deferred Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-17net ipv6: Prevent neighbor add if protocol is disabled on deviceDavid Ahern
Disabling IPv6 on an interface removes existing entries but nothing prevents new entries from being manually added. To that end, add a new neigh_table operation, allow_add, that is called on RTM_NEWNEIGH to see if neighbor entries are allowed on a given device. If IPv6 is disabled on the device, allow_add returns false and passes a message back to the user via extack. $ echo 1 > /proc/sys/net/ipv6/conf/eth1/disable_ipv6 $ ip -6 neigh add fe80::4c88:bff:fe21:2704 dev eth1 lladdr de:ad:be:ef:01:01 Error: IPv6 is disabled on this device. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-08neighbor: Add skip_cache argument to neigh_outputDavid Ahern
A later patch allows an IPv6 gateway with an IPv4 route. The neighbor entry will exist in the v6 ndisc table and the cached header will contain the ipv6 protocol which is wrong for an IPv4 packet. For an IPv4 packet to use the v6 neighbor entry, neigh_output needs to skip the cached header and just use the output callback for the neigh entry. A future patchset can look at expanding the hh_cache to handle 2 protocols. For now, IPv6 gateways with an IPv4 route will take the extra overhead of generating the header. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19neighbour: register rtnl doit handlerRoopa Prabhu
this patch registers neigh doit handler. The doit handler returns a neigh entry given dst and dev. This is similar to route and fdb doit (get) handlers. Also moves nda_policy declaration from rtnetlink.c to neighbour.c Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Reviewed-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-16neighbor: Add protocol attributeDavid Ahern
Similar to routes and rules, add protocol attribute to neighbor entries for easier tracking of how each was created. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-15neighbor: Improve neighbour struct layoutDavid Ahern
Move arp_queue_len_bytes ahead of arp_queue to remove two 4-byte holes. Ensure ha element is always 8-byte aligned. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14neighbor: Move neigh_update_ext_learned to core fileDavid Ahern
neigh_update_ext_learned has one caller in neighbour.c so does not need to be defined in the header. Move it and in the process remove the intialization of ndm_flags and just set it based on the flags check. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several conflicts, seemingly all over the place. I used Stephen Rothwell's sample resolutions for many of these, if not just to double check my own work, so definitely the credit largely goes to him. The NFP conflict consisted of a bug fix (moving operations past the rhashtable operation) while chaning the initial argument in the function call in the moved code. The net/dsa/master.c conflict had to do with a bug fix intermixing of making dsa_master_set_mtu() static with the fixing of the tagging attribute location. cls_flower had a conflict because the dup reject fix from Or overlapped with the addition of port range classifiction. __set_phy_supported()'s conflict was relatively easy to resolve because Andrew fixed it in both trees, so it was just a matter of taking the net-next copy. Or at least I think it was :-) Joe Stringer's fix to the handling of netns id 0 in bpf_sk_lookup() intermixed with changes on how the sdif and caller_net are calculated in these code paths in net-next. The remaining BPF conflicts were largely about the addition of the __bpf_md_ptr stuff in 'net' overlapping with adjustments and additions to the relevant data structure where the MD pointer macros are used. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07neighbour: Avoid writing before skb->head in neigh_hh_output()Stefano Brivio
While skb_push() makes the kernel panic if the skb headroom is less than the unaligned hardware header size, it will proceed normally in case we copy more than that because of alignment, and we'll silently corrupt adjacent slabs. In the case fixed by the previous patch, "ipv6: Check available headroom in ip6_xmit() even without options", we end up in neigh_hh_output() with 14 bytes headroom, 14 bytes hardware header and write 16 bytes, starting 2 bytes before the allocated buffer. Always check we're not writing before skb->head and, if the headroom is not enough, warn and drop the packet. v2: - instead of panicking with BUG_ON(), WARN_ON_ONCE() and drop the packet (Eric Dumazet) - if we avoid the panic, though, we need to explicitly check the headroom before the memcpy(), otherwise we'll have corrupted slabs on a running kernel, after we warn - use __skb_push() instead of skb_push(), as the headroom check is already implemented here explicitly (Eric Dumazet) Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07neighbor: Improve garbage collectionDavid Ahern
The existing garbage collection algorithm has a number of problems: 1. The gc algorithm will not evict PERMANENT entries as those entries are managed by userspace, yet the existing algorithm walks the entire hash table which means it always considers PERMANENT entries when looking for entries to evict. In some use cases (e.g., EVPN) there can be tens of thousands of PERMANENT entries leading to wasted CPU cycles when gc kicks in. As an example, with 32k permanent entries, neigh_alloc has been observed taking more than 4 msec per invocation. 2. Currently, when the number of neighbor entries hits gc_thresh2 and the last flush for the table was more than 5 seconds ago gc kicks in walks the entire hash table evicting *all* entries not in PERMANENT or REACHABLE state and not marked as externally learned. There is no discriminator on when the neigh entry was created or if it just moved from REACHABLE to another NUD_VALID state (e.g., NUD_STALE). It is possible for entries to be created or for established neighbor entries to be moved to STALE (e.g., an external node sends an ARP request) right before the 5 second window lapses: -----|---------x|----------|----- t-5 t t+5 If that happens those entries are evicted during gc causing unnecessary thrashing on neighbor entries and userspace caches trying to track them. Further, this contradicts the description of gc_thresh2 which says "Entries older than 5 seconds will be cleared". One workaround is to make gc_thresh2 == gc_thresh3 but that negates the whole point of having separate thresholds. 3. Clearing *all* neigh non-PERMANENT/REACHABLE/externally learned entries when gc_thresh2 is exceeded is over kill and contributes to trashing especially during startup. This patch addresses these problems as follows: 1. Use of a separate list_head to track entries that can be garbage collected along with a separate counter. PERMANENT entries are not added to this list. The gc_thresh parameters are only compared to the new counter, not the total entries in the table. The forced_gc function is updated to only walk this new gc_list looking for entries to evict. 2. Entries are added to the list head at the tail and removed from the front. 3. Entries are only evicted if they were last updated more than 5 seconds ago, adhering to the original intent of gc_thresh2. 4. Forced gc is stopped once the number of gc_entries drops below gc_thresh2. 5. Since gc checks do not apply to PERMANENT entries, gc levels are skipped when allocating a new neighbor for a PERMANENT entry. By extension this means there are no explicit limits on the number of PERMANENT entries that can be created, but this is no different than FIB entries or FDB entries. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-12net: Evict neighbor entries on carrier downDavid Ahern
When a link's carrier goes down it could be a sign of the port changing networks. If the new network has overlapping addresses with the old one, then the kernel will continue trying to use neighbor entries established based on the old network until the entries finally age out - meaning a potentially long delay with communications not working. This patch evicts neighbor entries on carrier down with the exception of those marked permanent. Permanent entries are managed by userspace (either an admin or a routing daemon such as FRR). Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-24neighbour: send netlink notification if NTF_ROUTER changesRoopa Prabhu
send netlink notification if neigh_update results in NTF_ROUTER change and if NEIGH_UPDATE_F_ISROUTER is on. Also move the NTF_ROUTER change function into a helper. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-25neighbour: support for NTF_EXT_LEARNED flagRoopa Prabhu
This patch extends NTF_EXT_LEARNED support to the neighbour system. Example use-case: An Ethernet VPN implementation (eg in FRR routing suite) can use this flag to add dynamic reachable external neigh entires learned via control plane. The use of neigh NTF_EXT_LEARNED in this patch is consistent with its use with bridge and vxlan fdb entries. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-25neigh: make strucrt neigh_table::entry_size unsigned intAlexey Dobriyan
Key length can't be negative. Leave comparisons against nla_len() signed just in case truncated attribute can sneak in there. Space savings: add/remove: 0/0 grow/shrink: 0/7 up/down: 0/-7 (-7) function old new delta pneigh_delete 273 272 -1 mlx5e_rep_netevent_event 1415 1414 -1 mlx5e_create_encap_header_ipv6 1194 1193 -1 mlx5e_create_encap_header_ipv4 1071 1070 -1 cxgb4_l2t_get 1104 1103 -1 __pneigh_lookup 69 68 -1 __neigh_create 2452 2451 -1 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-25neigh: make struct neigh_table::entry_size unsigned intAlexey Dobriyan
Neigh entry size can't be negative. Space savings: add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-7 (-7) function old new delta lowpan_neigh_construct 25 24 -1 clip_seq_sub_iter 152 151 -1 clip_ioctl 1475 1474 -1 clip_constructor 93 92 -1 __neigh_create 2455 2452 -3 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-19Merge tag 'gcc-plugins-v4.13-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull structure randomization updates from Kees Cook: "Now that IPC and other changes have landed, enable manual markings for randstruct plugin, including the task_struct. This is the rest of what was staged in -next for the gcc-plugins, and comes in three patches, largest first: - mark "easy" structs with __randomize_layout - mark task_struct with an optional anonymous struct to isolate the __randomize_layout section - mark structs to opt _out_ of automated marking (which will come later) And, FWIW, this continues to pass allmodconfig (normal and patched to enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and s390 for me" * tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: randstruct: opt-out externally exposed function pointer structs task_struct: Allow randomized layout randstruct: Mark various structs for randomization
2017-07-01net: convert neigh_params.refcnt from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert neighbour.refcnt from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-30randstruct: Mark various structs for randomizationKees Cook
This marks many critical kernel structures for randomization. These are structures that have been targeted in the past in security exploits, or contain functions pointers, pointers to function pointer tables, lists, workqueues, ref-counters, credentials, permissions, or are otherwise sensitive. This initial list was extracted from Brad Spengler/PaX Team's code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Left out of this list is task_struct, which requires special handling and will be covered in a subsequent patch. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-06-04neigh: Really delete an arp/neigh entry on "ip neigh delete" or "arp -d"Sowmini Varadhan
The command # arp -s 62.2.0.1 a:b:c:d:e:f dev eth2 adds an entry like the following (listed by "arp -an") ? (62.2.0.1) at 0a:0b:0c:0d:0e:0f [ether] PERM on eth2 but the symmetric deletion command # arp -i eth2 -d 62.2.0.1 does not remove the PERM entry from the table, and instead leaves behind ? (62.2.0.1) at <incomplete> on eth2 The reason is that there is a refcnt of 1 for the arp_tbl itself (neigh_alloc starts off the entry with a refcnt of 1), thus the neigh_release() call from arp_invalidate() will (at best) just decrement the ref to 1, but will never actually free it from the table. To fix this, we need to do something like neigh_forced_gc: if the refcnt is 1 (i.e., on the table's ref), remove the entry from the table and free it. This patch refactors and shares common code between neigh_forced_gc and the newly added neigh_remove_one. A similar issue exists for IPv6 Neighbor Cache entries, and is fixed in a similar manner by this patch. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-12net: neigh: make ->hh_len 32-bitAlexey Dobriyan
Using 16-bit ->hh_len doesn't save any memory, save some .text instead: add/remove: 0/0 grow/shrink: 1/6 up/down: 2/-19 (-17) function old new delta neigh_update 2312 2314 +2 fwnet_header_cache 199 197 -2 eth_header_cache 101 99 -2 ip6_finish_output2 2371 2368 -3 vrf_finish_output6 1522 1518 -4 vrf_finish_output 1413 1409 -4 ip_finish_output2 1627 1623 -4 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22neighbour: fix nlmsg_pid in notificationsRoopa Prabhu
neigh notifications today carry pid 0 for nlmsg_pid in all cases. This patch fixes it to carry calling process pid when available. Applications (eg. quagga) rely on nlmsg_pid to ignore notifications generated by their own netlink operations. This patch follows the routing subsystem which already sets this correctly. Reported-by: Vivek Venkatraman <vivek@cumulusnetworks.com> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>