Re: [PATCH net v3] net: reduce XMIT_RECURSION_LIMIT under KASAN

From: kernel test robot

Date: Wed Aug 12 2026 - 05:03:04 EST

Hello,

kernel test robot noticed "kselftests-bpf.net/forwarding fail" on:

commit: ef83ebe178d46ab0d26a906be5fcd654a488c730 ("[PATCH net v3] net: reduce XMIT_RECURSION_LIMIT under KASAN")
url: https://github.com/intel-lab-lkp/linux/commits/Tristan-Madani/net-reduce-XMIT_RECURSION_LIMIT-under-KASAN/20260728-072802
base: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git bd0e9289e2642f6a5c54faad304ce0f41e926d22
patch link: https://lore.kernel.org/all/20260727200454.4048141-1-tristmd@xxxxxxxxx/
patch subject: [PATCH net v3] net: reduce XMIT_RECURSION_LIMIT under KASAN

in testcase: kselftests-bpf
version:
with following parameters:

group: net/forwarding
failed cases:
forwarding.custom_multipath_hash.sh
forwarding.vxlan_asymmetric.sh
forwarding.vxlan_asymmetric_ipv6.sh
forwarding.vxlan_symmetric.sh
forwarding.vxlan_symmetric_ipv6.sh

config: x86_64-rhel-9.4-bpf
compiler: gcc-14
test machine: 16 threads Intel(R) Core(TM) i7-13620H (Raptor Lake) with 32G memory

(please refer to attached dmesg/kmsg for entire log/backtrace)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <yi1.lai@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-lkp/202608121039.ca91f25a-lkp@xxxxxxxxx

KERNEL SELFTESTS: linux_headers_dir is /usr/src/linux-headers-x86_64-rhel-9.4-bpf-ef83ebe178d46ab0d26a906be5fcd654a488c730
2026-08-04 22:51:54 sed -i s/default_timeout=45/default_timeout=300/ kselftest/runner.sh
2026-08-04 22:51:54 make -j16 TARGETS=net/forwarding run_tests
# timeout set to 0
# selftests: net/forwarding: custom_multipath_hash.sh
# TEST: ping [ OK ]
# TEST: ping6 [ OK ]
# INFO: Running IPv4 custom multipath hash tests
# TEST: Multipath hash field: Source IP (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 6600 / 6001
# TEST: Multipath hash field: Source IP (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 0 / 12600
# TEST: Multipath hash field: Destination IP (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 5950 / 6650
# TEST: Multipath hash field: Destination IP (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 0 / 12600
# TEST: Multipath hash field: Source port (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 16505 / 16265
# TEST: Multipath hash field: Source port (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 0 / 32771
# TEST: Multipath hash field: Destination port (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 16504 / 16266
# TEST: Multipath hash field: Destination port (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 32769 / 0
# INFO: Running IPv6 custom multipath hash tests
# TEST: Multipath hash field: Source IP (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 6102 / 6500
# TEST: Multipath hash field: Source IP (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 12600 / 0
# TEST: Multipath hash field: Destination IP (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 6100 / 6500
# TEST: Multipath hash field: Destination IP (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 12600 / 0
# TEST: Multipath hash field: Flowlabel (balanced) [FAIL]
# Expected traffic to be balanced, but it is not
# INFO: Packets sent on path1 / path2: 1 / 0
# TEST: Multipath hash field: Flowlabel (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 0 / 12600
# TEST: Multipath hash field: Source port (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 16422 / 16347
# TEST: Multipath hash field: Source port (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 32771 / 0
# TEST: Multipath hash field: Destination port (balanced) [ OK ]
# INFO: Packets sent on path1 / path2: 16422 / 16347
# TEST: Multipath hash field: Destination port (unbalanced) [ OK ]
# INFO: Packets sent on path1 / path2: 32769 / 0
not ok 17 selftests: net/forwarding: custom_multipath_hash.sh # exit=1

# selftests: net/forwarding: vxlan_asymmetric.sh
# RTNETLINK answers: File exists
# RTNETLINK answers: File exists
# TEST: ping: local->local vid 10->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 10 [ OK ]
# TEST: ping: local->remote vid 20->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 20 [FAIL]
# TEST: ping: local->remote vid 20->vid 10 [FAIL]
# INFO: deleting neighbours from vlan interfaces
# TEST: ping: local->local vid 10->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 10 [ OK ]
# TEST: ping: local->remote vid 20->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 20 [FAIL]
# TEST: ping: local->remote vid 20->vid 10 [FAIL]

# selftests: net/forwarding: vxlan_asymmetric_ipv6.sh
# TEST: ping6: local->local vid 10->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 10 [ OK ]
# TEST: ping6: local->remote vid 20->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 20 [FAIL]
# TEST: ping6: local->remote vid 20->vid 10 [FAIL]
# INFO: deleting neighbours from vlan interfaces
# TEST: ping6: local->local vid 10->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 10 [ OK ]
# TEST: ping6: local->remote vid 20->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 20 [FAIL]
# TEST: ping6: local->remote vid 20->vid 10 [FAIL]
not ok 100 selftests: net/forwarding: vxlan_asymmetric_ipv6.sh # exit=1

# selftests: net/forwarding: vxlan_symmetric.sh
# RTNETLINK answers: File exists
# RTNETLINK answers: File exists
# TEST: ping: local->local vid 10->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 10 [ OK ]
# TEST: ping: local->remote vid 20->vid 20 [ OK ]
# TEST: ping: local->remote vid 10->vid 20 [FAIL]
# TEST: ping: local->remote vid 20->vid 10 [FAIL]
not ok 111 selftests: net/forwarding: vxlan_symmetric.sh # exit=1

# timeout set to 0
# selftests: net/forwarding: vxlan_symmetric_ipv6.sh
# TEST: ping6: local->local vid 10->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 10 [ OK ]
# TEST: ping6: local->remote vid 20->vid 20 [ OK ]
# TEST: ping6: local->remote vid 10->vid 20 [FAIL]
# TEST: ping6: local->remote vid 20->vid 10 [FAIL]
not ok 112 selftests: net/forwarding: vxlan_symmetric_ipv6.sh # exit=1

The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260812/202608121039.ca91f25a-lkp@xxxxxxxxx

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki