kernel/linux.git/net/netlink, branch v6.18.35

net: netlink: don't set nsid on local notifications

2026-06-09T10:28:25+00:00

[ Upstream commit 88b126b39f9757e9debc322d4679239e9af089c7 ] In most cases, notifications on sockets with NETLINK_LISTEN_ALL_NSID do not contain NSID in their ancillary data in case the event is local to the listener. However, when a self-referential NSID is allocated for a namespace, every local notification starts sending this ID to the user space. This is problematic, because the listener cannot tell if those notifications are local or not anymore without making extra requests to figure out if the provided NSID is local or not. The listener can also not figure out the local NSID beforehand as it can be allocated at any point in time by other processes, changing the structure of the future notifications for everyone. The value is practically not useful, since it's the namespace's own ID that the application has to obtain from other sources in order to figure out if it's the same or not. So, for the application it's just an extra busy work with no benefits. Moreover, applications that do not know about this quirk may be mishandling notifications with NSID set as notifications from remote namespaces. This is the case for ovs-vswitchd and the iproute2's 'ip monitor' that stops printing 'current' and starts printing the nsid number mid-session. Lack of clear documentation for this behavior is also not helping. A search though open-source projects doesn't reveal any projects that use NETNSA_NSID_NOT_ASSIGNED and rely on metadata to contain self-referential NSIDs (expected, since the value is not useful). Quite the opposite, as already mentioned, there are few applications that rely on NSID to not be present in local events. Since the value is not useful and actively harmful in some cases, let's not report it for local events, making the notifications more consistent. Also adding some blank lines for readability. Fixes: 59324cf35aba ("netlink: allow to listen "all" netns") Reported-by: Matteo Perin Signed-off-by: Ilya Maximets Acked-by: Nicolas Dichtel Link: https://patch.msgid.link/20260520172317.175168-3-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: netlink: fix sending unassigned nsid after assigned one

2026-06-09T10:28:25+00:00

[ Upstream commit 70f8592ee90585272018a725054b6eb2ab7e99ca ] If the current skb is not shared, it is re-used directly for all the sockets subscribed to the notification. If we have remote all-nsid socket receiving a message first, then the 'nsid_is_set' will be set to 'true'. If the nsid is NOT_ASSIGNED for the next socket in the list, the 'nsid_is_set' will remain 'true' and the negative value is be delivered to the user space. All subsequent nsid values will be delivered as well, since there is no code path that sets the flag back to 'false'. Fix that by always dropping the flag to 'false' first. Fixes: 7212462fa6fd ("netlink: don't send unknown nsid") Signed-off-by: Ilya Maximets Acked-by: Nicolas Dichtel Link: https://patch.msgid.link/20260520172317.175168-2-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-09-12T00:40:13+00:00

Cross-merge networking fixes after downstream PR (net-6.17-rc6). Conflicts: net/netfilter/nft_set_pipapo.c net/netfilter/nft_set_pipapo_avx2.c c4eaca2e1052 ("netfilter: nft_set_pipapo: don't check genbit from packetpath lookups") 84c1da7b38d9 ("netfilter: nft_set_pipapo: use avx2 algorithm for insertions too") Only trivial adjacent changes (in a doc and a Makefile). Signed-off-by: Jakub Kicinski

genetlink: fix genl_bind() invoking bind() after -EPERM

2025-09-09T00:50:36+00:00

Per family bind/unbind callbacks were introduced to allow families to track multicast group consumer presence, e.g. to start or stop producing events depending on listeners. However, in genl_bind() the bind() callback was invoked even if capability checks failed and ret was set to -EPERM. This means that callbacks could run on behalf of unauthorized callers while the syscall still returned failure to user space. Fix this by only invoking bind() after "if (ret) break;" check i.e. after permission checks have succeeded. Fixes: 3de21a8990d3 ("genetlink: Add per family bind/unbind callbacks") Signed-off-by: Alok Tiwari Link: https://patch.msgid.link/20250905135731.3026965-1-alok.a.tiwari@oracle.com Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-09-04T20:33:00+00:00

Cross-merge networking fixes after downstream PR (net-6.17-rc5). No conflicts. Adjacent changes: include/net/sock.h c51613fa276f ("net: add sk->sk_drop_counters") 5d6b58c932ec ("net: lockless sock_i_ino()") Signed-off-by: Jakub Kicinski

net: lockless sock_i_ino()

2025-09-03T23:08:24+00:00

Followup of commit c51da3f7a161 ("net: remove sock_i_uid()") A recent syzbot report was the trigger for this change. Over the years, we had many problems caused by the read_lock[_bh](&sk->sk_callback_lock) in sock_i_uid(). We could fix smc_diag_dump_proto() or make a more radical move: Instead of waiting for new syzbot reports, cache the socket inode number in sk->sk_ino, so that we no longer need to acquire sk->sk_callback_lock in sock_i_ino(). This makes socket dumps faster (one less cache line miss, and two atomic ops avoided). Prior art: commit 25a9c8a4431c ("netlink: Add __sock_i_ino() for __netlink_diag_dump().") commit 4f9bf2a2f5aa ("tcp: Don't acquire inet_listen_hashbucket::lock with disabled BH.") commit efc3dbc37412 ("rds: Make rds_sock_lock BH rather than IRQ safe.") Fixes: d2d6422f8bd1 ("x86: Allow to enable PREEMPT_RT.") Reported-by: syzbot+50603c05bbdf4dfdaffa@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68b73804.050a0220.3db4df.01d8.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Sebastian Andrzej Siewior Link: https://patch.msgid.link/20250902183603.740428-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: add sk_drops_read(), sk_drops_inc() and sk_drops_reset() helpers

2025-08-28T11:14:50+00:00

We want to split sk->sk_drops in the future to reduce potential contention on this field. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250826125031.1578842-2-edumazet@google.com Signed-off-by: Paolo Abeni

netlink: avoid infinite retry looping in netlink_unicast()

2025-07-31T02:16:49+00:00

netlink_attachskb() checks for the socket's read memory allocation constraints. Firstly, it has: rmem < READ_ONCE(sk->sk_rcvbuf) to check if the just increased rmem value fits into the socket's receive buffer. If not, it proceeds and tries to wait for the memory under: rmem + skb->truesize > READ_ONCE(sk->sk_rcvbuf) The checks don't cover the case when skb->truesize + sk->sk_rmem_alloc is equal to sk->sk_rcvbuf. Thus the function neither successfully accepts these conditions, nor manages to reschedule the task - and is called in retry loop for indefinite time which is caught as: rcu: INFO: rcu_sched self-detected stall on CPU rcu: 0-....: (25999 ticks this GP) idle=ef2/1/0x4000000000000000 softirq=262269/262269 fqs=6212 (t=26000 jiffies g=230833 q=259957) NMI backtrace for cpu 0 CPU: 0 PID: 22 Comm: kauditd Not tainted 5.10.240 #68 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc42 04/01/2014 Call Trace: dump_stack lib/dump_stack.c:120 nmi_cpu_backtrace.cold lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace lib/nmi_backtrace.c:62 rcu_dump_cpu_stacks kernel/rcu/tree_stall.h:335 rcu_sched_clock_irq.cold kernel/rcu/tree.c:2590 update_process_times kernel/time/timer.c:1953 tick_sched_handle kernel/time/tick-sched.c:227 tick_sched_timer kernel/time/tick-sched.c:1399 __hrtimer_run_queues kernel/time/hrtimer.c:1652 hrtimer_interrupt kernel/time/hrtimer.c:1717 __sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1113 asm_call_irq_on_stack arch/x86/entry/entry_64.S:808 netlink_attachskb net/netlink/af_netlink.c:1234 netlink_unicast net/netlink/af_netlink.c:1349 kauditd_send_queue kernel/audit.c:776 kauditd_thread kernel/audit.c:897 kthread kernel/kthread.c:328 ret_from_fork arch/x86/entry/entry_64.S:304 Restore the original behavior of the check which commit in Fixes accidentally missed when restructuring the code. Found by Linux Verification Center (linuxtesting.org). Fixes: ae8f160e7eb2 ("netlink: Fix wraparounds of sk->sk_rmem_alloc.") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250728080727.255138-1-pchelkin@ispras.ru Signed-off-by: Jakub Kicinski

Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-07-30T16:58:50+00:00

Pull bpf updates from Alexei Starovoitov: - Remove usermode driver (UMD) framework (Thomas Weißschuh) - Introduce Strongly Connected Component (SCC) in the verifier to detect loops and refine register liveness (Eduard Zingerman) - Allow 'void *' cast using bpf_rdonly_cast() and corresponding '__arg_untrusted' for global function parameters (Eduard Zingerman) - Improve precision for BPF_ADD and BPF_SUB operations in the verifier (Harishankar Vishwanathan) - Teach the verifier that constant pointer to a map cannot be NULL (Ihor Solodrai) - Introduce BPF streams for error reporting of various conditions detected by BPF runtime (Kumar Kartikeya Dwivedi) - Teach the verifier to insert runtime speculation barrier (lfence on x86) to mitigate speculative execution instead of rejecting the programs (Luis Gerhorst) - Various improvements for 'veristat' (Mykyta Yatsenko) - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to improve bug detection by syzbot (Paul Chaignon) - Support BPF private stack on arm64 (Puranjay Mohan) - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's node (Song Liu) - Introduce kfuncs for read-only string opreations (Viktor Malik) - Implement show_fdinfo() for bpf_links (Tao Chen) - Reduce verifier's stack consumption (Yonghong Song) - Implement mprog API for cgroup-bpf programs (Yonghong Song) * tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits) selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite selftests/bpf: Add selftest for attaching tracing programs to functions in deny list bpf: Add log for attaching tracing programs to functions in deny list bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions bpf: Fix various typos in verifier.c comments bpf: Add third round of bounds deduction selftests/bpf: Test invariants on JSLT crossing sign selftests/bpf: Test cross-sign 64bits range refinement selftests/bpf: Update reg_bound range refinement logic bpf: Improve bounds when s64 crosses sign boundary bpf: Simplify bounds refinement from s32 selftests/bpf: Enable private stack tests for arm64 bpf, arm64: JIT support for private stack bpf: Move bpf_jit_get_prog_name() to core.c bpf, arm64: Fix fp initialization for exception boundary umd: Remove usermode driver framework bpf/preload: Don't select USERMODE_DRIVER selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure selftests/bpf: Increase xdp data size for arm64 64K page size ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc6

2025-07-18T19:15:59+00:00

Cross-merge BPF and other fixes after downstream PR. No conflicts. Signed-off-by: Alexei Starovoitov