kernel/linux.git/tools/testing/selftests/net, branch v6.18.34

selftests: net: Fix checksums in xdp_native

2026-06-01T15:51:07+00:00

[ Upstream commit dfc077043351a81887d1e4c9ac244e9243f3cbf2 ] Data adjustment cases failed with "Data exchange failed" when using IPv4 because the program did not update the IP and UDP checksums in the IPv4 branch. The issue was masked when both IPv4 and IPv6 were configured, since the test harness prefers IPv6. While here, generalize csum_fold_helper() to fold twice so it works for any 32-bit input. Fixes: 0b65cfcef9c5 ("selftests: drv-net: Test tail-adjustment support") Reviewed-by: Carolina Jubran Reviewed-by: Dragos Tatulea Signed-off-by: Nimrod Oren Link: https://patch.msgid.link/20260520153928.3371765-1-noren@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: send a challenge ACK on SEG.ACK > SND.NXT

2026-05-23T11:07:05+00:00

[ Upstream commit 42726ec644cbdde0035c3e0417fee8ed9547e120 ] RFC 5961 Section 5.2 validates an incoming segment's ACK value against the range [SND.UNA - MAX.SND.WND, SND.NXT] and states: "All incoming segments whose ACK value doesn't satisfy the above condition MUST be discarded and an ACK sent back." Commit 354e4aa391ed ("tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation") opted Linux into this mitigation and implements the challenge ACK on the lower side (SEG.ACK < SND.UNA - MAX.SND.WND), but the symmetric upper side (SEG.ACK > SND.NXT) still takes the pre-RFC-5961 path and silently returns SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, even though RFC 793 Section 3.9 (now RFC 9293 Section 3.10.7.4) has always required: "If the ACK acknowledges something not yet sent (SEG.ACK > SND.NXT) then send an ACK, drop the segment, and return." Complete the mitigation by sending a challenge ACK on that branch, reusing the existing tcp_send_challenge_ack() path which already enforces the per-socket RFC 5961 Section 7 rate limit via __tcp_oow_rate_limited(). FLAG_NO_CHALLENGE_ACK is honoured for symmetry with the lower-edge case. Update the existing tcp_ts_recent_invalid_ack.pkt selftest, which drives this exact path, to consume the new challenge ACK. Fixes: 354e4aa391ed ("tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation") Signed-off-by: Jiayuan Chen Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260422123605.320000-2-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

selftests: netfilter: nft_tproxy.sh: adjust to socat changes

2026-05-23T11:06:32+00:00

[ Upstream commit 61119542663cac70898aef532eb57ee41ea9b477 ] Like e65d8b6f3092 ("selftests: drv-net: adjust to socat changes") we need to add shut-none for this test too. The extra 0-packet can trigger a second (unexpected) reply from the server. Fixes: 7e37e0eacd22 ("selftests: netfilter: nft_tproxy.sh: add tcp tests") Reported-by: Jakub Kicinski Closes: https://lore.kernel.org/netdev/20260408152432.24b8ad0d@kernel.org/ Suggested-by: Jakub Kicinski Signed-off-by: Florian Westphal Link: https://patch.msgid.link/20260409224506.27072-1-fw@strlen.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

selftests: mptcp: pm: restrict 'unknown' check to pm_nl_ctl

2026-05-14T13:30:22+00:00

commit 53705ddfa18408f8e1f064331b6387509fa19f7f upstream. When pm_netlink.sh is executed with '-i', 'ip mptcp' is used instead of 'pm_nl_ctl'. IPRoute2 doesn't support the 'unknown' flag, which has only been added to 'pm_nl_ctl' for this specific check: to ensure that the kernel ignores such unsupported flag. No reason to add this flag to 'ip mptcp'. Then, this check should be skipped when 'ip mptcp' is used. Fixes: 0cef6fcac24d ("selftests: mptcp: ip_mptcp option for more scripts") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-11-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

selftests: mptcp: check output: catch cmd errors

2026-05-14T13:30:22+00:00

commit 65db7b27b90e2ea8d4966935aa9a50b6a60c31ac upstream. Using '${?}' inside the if-statement to check the returned value from the command that was evaluated as part of the if-statement is not correct: here, '${?}' will be linked to the previous instruction, not the one that is expected here (${cmd}). Instead, simply mark the error, except if an error is expected. If that's the case, 1 can be passed as the 4th argument of this helper. Three checks from pm_netlink.sh expect an error. While at it, improve the error message when the command unexpectedly fails or succeeds. Note that we could expect a specific returned value, but the checks currently expecting an error can be used with 'ip mptcp' or 'pm_nl_ctl', and these two tools don't return the same error code. Fixes: 2d0c1d27ea4e ("selftests: mptcp: add mptcp_lib_check_output helper") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-10-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

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

2026-04-22T11:22:22+00:00

[ Upstream commit efaa71faf212324ecbf6d5339e9717fe53254f58 ] 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 Signed-off-by: Sasha Levin

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

2026-03-12T11:09:44+00:00

commit 1777f349ff41b62dfe27454b69c27b0bc99ffca5 upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2026-03-12T11:09:43+00:00

commit 560edd99b5f58b2d4bbe3c8e51e1eed68d887b0e upstream. 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 Signed-off-by: Greg Kroah-Hartman

selftests: mptcp: more stable simult_flows tests

2026-03-12T11:09:43+00:00

commit 8c09412e584d9bcc0e71d758ec1008d1c8d1a326 upstream. By default, the netem qdisc can keep up to 1000 packets under its belly to deal with the configured rate and delay. The simult flows test-case simulates very low speed links, to avoid problems due to slow CPUs and the TCP stack tend to transmit at a slightly higher rate than the (virtual) link constraints. All the above causes a relatively large amount of packets being enqueued in the netem qdiscs - the longer the transfer, the longer the queue - producing increasingly high TCP RTT samples and consequently increasingly larger receive buffer size due to DRS. When the receive buffer size becomes considerably larger than the needed size, the tests results can flake, i.e. because minimal inaccuracy in the pacing rate can lead to a single subflow usage towards the end of the connection for a considerable amount of data. Address the issue explicitly setting netem limits suitable for the configured link speeds and unflake all the affected tests. Fixes: 1a418cb8e888 ("mptcp: simult flow self-tests") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260303-net-mptcp-misc-fixes-7-0-rc2-v1-1-4b5462b6f016@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

selftests: tc_actions: don't dump 2MB of \0 to stdout

2026-02-26T22:59:40+00:00

[ Upstream commit 32b70e62034aa72f8414ad4e9122cce7ad418c48 ] Since we started running selftests in NIPA we have been seeing tc_actions.sh generate a soft lockup warning on ~20% of the runs. On the pre-netdev foundation setup it was actually a missed irq splat from the console. Now it's either that or a lockup. I initially suspected a socket locking issue since the test is exercising local loopback with act_mirred. After hours of staring at this I noticed in strace that ncat when -o $file is specified _both_ saves the output to the file and still prints it to stdout. Because the file being sent is constructed with: dd conv=sparse status=none if=/dev/zero bs=1M count=2 of=$mirred ^^^^^^^^^ the data printed is all \0. Most terminals don't display nul characters (and neither does vng output capture save them). But QEMU's serial console still has to poke them thru which is very slow and causes the lockup (if the file is >600kB). Replace the '-o $file' with '> $file'. This speeds the test up from 2m20s to 18s on debug kernels, and prevents the warnings. Fixes: ca22da2fbd69 ("act_mirred: use the backlog for nested calls to mirred ingress") Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260214035159.2119699-1-kuba@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin