linux/tools/testing/selftests/net, branch v7.0

selftests: nft_queue.sh: add a parallel stress test

2026-04-08T11:34:51Z

Introduce a new stress test to check for race conditions in the nfnetlink_queue subsystem, where an entry is freed while another CPU is concurrently walking the global rhashtable. To trigger this, `nf_queue.c` is extended with two new flags: * -O (out-of-order): Buffers packet IDs and flushes them in reverse. * -b (bogus verdicts): Floods the kernel with non-existent packet IDs. The bogus verdict loop forces the kernel's lookup function to perform full rhashtable bucket traversals (-ENOENT). Combined with reverse-order flushing and heavy parallel UDP/ping flooding across 8 queues, this puts the nfnetlink_queue code under pressure. Joint work with Florian Westphal. Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Florian Westphal

selftests: seg6: add test for dst_cache isolation in seg6 lwtunnel

2026-04-08T03:20:56Z

Add a selftest that verifies the dst_cache in seg6 lwtunnel is not shared between the input (forwarding) and output (locally generated) paths. The test creates three namespaces (ns_src, ns_router, ns_dst) connected in a line. An SRv6 encap route on ns_router encapsulates traffic destined to cafe::1 with SID fc00::100. The SID is reachable only for forwarded traffic (from ns_src) via an ip rule matching the ingress interface (iif veth-r0 lookup 100), and blackholed in the main table. The test verifies that: 1. A packet generated locally on ns_router does not reach ns_dst with an empty cache, since the SID is blackholed; 2. A forwarded packet from ns_src populates the input cache from table 100 and reaches ns_dst; 3. A packet generated locally on ns_router still does not reach ns_dst after the input cache is populated, confirming the output path does not reuse the input cache entry. Both the forwarded and local packets are pinned to the same CPU with taskset, since dst_cache is per-cpu. Cc: Shuah Khan Signed-off-by: Andrea Mayer Reviewed-by: Nicolas Dichtel Reviewed-by: Justin Iurman Link: https://patch.msgid.link/20260404004405.4057-3-andrea.mayer@uniroma2.it Signed-off-by: Jakub Kicinski

selftests: net: bridge_vlan_mcast: wait for h1 before querier check

2026-04-08T03:16:16Z

The querier-interval test adds h1 (currently a slave of the VRF created by simple_if_init) to a temporary bridge br1 acting as an outside IGMP querier. The kernel VRF driver (drivers/net/vrf.c) calls cycle_netdev() on every slave add and remove, toggling the interface admin-down then up. Phylink takes the PHY down during the admin-down half of that cycle. Since h1 and swp1 are cable-connected, swp1 also loses its link may need several seconds to re-negotiate. Use setup_wait_dev $h1 0 which waits for h1 to return to UP state, so the test can rely on the link being back up at this point. Fixes: 4d8610ee8bd77 ("selftests: net: bridge: add vlan mcast_querier_interval tests") Signed-off-by: Daniel Golle Reviewed-by: Alexander Sverdlin Link: https://patch.msgid.link/c830f130860fd2efae08bfb9e5b25fd028e58ce5.1775424423.git.daniel@makrotopia.org Signed-off-by: Jakub Kicinski

selftests: netfilter: nft_concat_range.sh: add check for flush+reload bug

2026-03-25T20:40:47Z

This test will fail without the preceding commit ("netfilter: nft_set_pipapo_avx2: fix match retart if found element is expired"): reject overlapping range on add 0s [ OK ] reload with flush /dev/stdin:59:32-52: Error: Could not process rule: File exists add element inet filter test { 10.0.0.29 . 10.0.2.29 } Reviewed-by: Stefano Brivio Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

selftest: net: Add GC test for temporary routes with exceptions.

2026-03-23T23:59:31Z

Without the prior commit, IPv6 GC cannot track exceptions tied to permanent routes if they were originally added as temporary routes. Let's add a test case for the issue. 1. Add temporary routes 2. Create exceptions for the temporary routes 3. Promote the routes to permanent routes 4. Check if GC can find and purge the exceptions A few notes: + At step 4, unlike other test cases, we cannot wait for $GC_WAIT_TIME. While the exceptions are always iterable via netlink (since it traverses the entire fib tree instead of tb6_gc_hlist), rt6_nh_dump_exceptions() skips expired entries. If we waited for the expiration time, we would be unable to distinguish whether the exceptions were truly purged by GC or just hidden due to being expired. + For the same reason, at step 2, we use ICMPv6 redirect message instead of Packet Too Big message. This is because MTU exceptions always have RTF_EXPIRES, and rt6_age_examine_exception() does not respect the period specified by net.ipv6.route.flush=1. + We add a neighbour entry for the redirect target with NTF_ROUTER. Without this, the exceptions would be removed at step 3 when the fib6_may_remove_gc_list() is called. Without the fix, the exceptions remain even after GC is triggered by sysctl -wq net.ipv6.route.flush=1. FAIL: Expected 0 routes, got 5 TEST: ipv6 route garbage collection (promote to permanent routes) [FAIL] With the fix, GC purges the exceptions properly. TEST: ipv6 route garbage collection (promote to permanent routes) [ OK ] Signed-off-by: Kuniyuki Iwashima Reviewed-by: David Ahern Link: https://patch.msgid.link/20260320072317.2561779-4-kuniyu@google.com Signed-off-by: Jakub Kicinski

selftests: rtnetlink: add neighbour update test

2026-03-12T02:04:55Z

Check that protocol and flags are updated correctly for neighbour and pneigh entries. Signed-off-by: Sabrina Dubroca Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/d28f72b5b4ff4c9ecbbbde06146a938dcc4c264a.1772894876.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski

selftests: net: add test for IPv4 route with loopback IPv6 nexthop

2026-03-05T15:53:17Z

Add a regression test for a kernel panic that occurs when an IPv4 route references an IPv6 nexthop object created on the loopback device. The test creates an IPv6 nexthop on lo, binds an IPv4 route to it, then triggers a route lookup via ping to verify the kernel does not crash. ./fib_nexthops.sh Tests passed: 249 Tests failed: 0 Reviewed-by: Ido Schimmel Signed-off-by: Jiayuan Chen Reviewed-by: David Ahern Link: https://patch.msgid.link/20260304113817.294966-3-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski

selftests: net: tun: don't abort XFAIL cases

2026-03-05T15:34:55Z

The tun UDP tunnel GSO fixture contains XFAIL-marked variants intended to exercise failure paths (e.g. EMSGSIZE / "Message too long"). Using ASSERT_EQ() in these tests aborts the subtest, which prevents the harness from classifying them as XFAIL and can make the overall net: tun test fail. Switch the relevant ASSERT_EQ() checks to EXPECT_EQ() so the subtests continue running and the failures are correctly reported and accounted as XFAIL where applicable. Signed-off-by: Sun Jian Link: https://patch.msgid.link/20260225111451.347923-2-sun.jian.kdev@gmail.com Signed-off-by: Jakub Kicinski

selftests: mptcp: join: check removing signal+subflow endp

2026-03-05T02:21:13Z

This validates the previous commit: endpoints with both the signal and subflow flags should always be marked as used even if it was not possible to create new subflows due to the MPTCP PM limits. For this test, an extra endpoint is created with both the signal and the subflow flags, and limits are set not to create extra subflows. In this case, an ADD_ADDR is sent, but no subflows are created. Still, the local endpoint is marked as used, and no warning is fired when removing the endpoint, after having sent a RM_ADDR. The 'Fixes' tag here below is the same as the one from the previous commit: this patch here is not fixing anything wrong in the selftests, but it validates the previous fix for an issue introduced by this commit ID. Fixes: 85df533a787b ("mptcp: pm: do not ignore 'subflow' if 'signal' flag is also set") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-5-4b5462b6f016@kernel.org Signed-off-by: Jakub Kicinski

selftests: mptcp: join: check RM_ADDR not sent over same subflow

2026-03-05T02:21:12Z

This validates the previous commit: RM_ADDR were sent over the first found active subflow which could be the same as the one being removed. It is more likely to loose this notification. For this check, RM_ADDR are explicitly dropped when trying to send them over the initial subflow, when removing the endpoint attached to it. If it is dropped, the test will complain because some RM_ADDR have not been received. Note that only the RM_ADDR are dropped, to allow the linked subflow to be quickly and cleanly closed. To only drop those RM_ADDR, a cBPF byte code is used. If the IPTables commands fail, that's OK, the tests will continue to pass, but not validate this part. This can be ignored: another subtest fully depends on such command, and will be marked as skipped. The 'Fixes' tag here below is the same as the one from the previous commit: this patch here is not fixing anything wrong in the selftests, but it validates the previous fix for an issue introduced by this commit ID. Fixes: 8dd5efb1f91b ("mptcp: send ack for rm_addr") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-3-4b5462b6f016@kernel.org Signed-off-by: Jakub Kicinski