FYI, we noticed the following commit (built with gcc-7): commit: f3f6f46e7935c5fe707b4a88124556d8b9f10c92 ("[PATCH] ipv4: fix a RCU-list bug in inet_dump_fib()") url: https://github.com/0day-ci/linux/commits/Qian-Cai/ipv4-fix-a-RCU-list-bug-in-inet_dump_fib/20200320-061342 in testcase: kernel-selftests with following parameters: group: kselftests-02 ucode: 0xd6 test-description: The kernel contains a set of "self tests" under the tools/testing/selftests/ directory. These are intended to be small unit tests to exercise individual code paths in the kernel. test-url: https://www.kernel.org/doc/Documentation/kselftest.txt on test machine: 8 threads Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz with 16G memory caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): If you fix the issue, kindly add following tag Reported-by: kernel test robot # selftests: net: pmtu.sh # TEST: ipv4: PMTU exceptions [ OK ] # TEST: ipv4: PMTU exceptions - nexthop objects [ OK ] # TEST: ipv6: PMTU exceptions [ OK ] # TEST: ipv6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over vxlan4: PMTU exceptions [ OK ] # TEST: IPv4 over vxlan4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over vxlan4: PMTU exceptions [ OK ] # TEST: IPv6 over vxlan4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over vxlan6: PMTU exceptions [ OK ] # TEST: IPv4 over vxlan6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over vxlan6: PMTU exceptions [ OK ] # TEST: IPv6 over vxlan6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over geneve4: PMTU exceptions [ OK ] # TEST: IPv4 over geneve4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over geneve4: PMTU exceptions [ OK ] # TEST: IPv6 over geneve4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over geneve6: PMTU exceptions [ OK ] # TEST: IPv4 over geneve6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over geneve6: PMTU exceptions [ OK ] # TEST: IPv6 over geneve6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over fou4: PMTU exceptions [ OK ] # TEST: IPv4 over fou4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over fou4: PMTU exceptions [ OK ] # TEST: IPv6 over fou4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over fou6: PMTU exceptions [ OK ] # TEST: IPv4 over fou6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over fou6: PMTU exceptions [ OK ] # TEST: IPv6 over fou6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over gue4: PMTU exceptions [ OK ] # TEST: IPv4 over gue4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over gue4: PMTU exceptions [ OK ] # TEST: IPv6 over gue4: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv4 over gue6: PMTU exceptions [ OK ] # TEST: IPv4 over gue6: PMTU exceptions - nexthop objects [ OK ] # TEST: IPv6 over gue6: PMTU exceptions [ OK ] # TEST: IPv6 over gue6: PMTU exceptions - nexthop objects [ OK ] # TEST: vti6: PMTU exceptions [ OK ] # TEST: vti4: PMTU exceptions [ OK ] # TEST: vti4: default MTU assignment [ OK ] # TEST: vti6: default MTU assignment [ OK ] # TEST: vti4: MTU setting on link creation [ OK ] # TEST: vti6: MTU setting on link creation [ OK ] # TEST: vti6: MTU changes on link changes [ OK ] # TEST: ipv4: cleanup of cached exceptions [ OK ] # TEST: ipv4: cleanup of cached exceptions - nexthop objects [ OK ] # TEST: ipv6: cleanup of cached exceptions [ OK ] # TEST: ipv6: cleanup of cached exceptions - nexthop objects [ OK ] # Segmentation fault # Segmentation fault # TEST: ipv4: list and flush cached exceptions [FAIL] # can't list cached exceptions # Segmentation fault # Segmentation fault # TEST: ipv4: list and flush cached exceptions - nexthop objects [FAIL] # can't list cached exceptions # TEST: ipv6: list and flush cached exceptions [ OK ] # TEST: ipv6: list and flush cached exceptions - nexthop objects [ OK ] not ok 16 selftests: net: pmtu.sh # exit=1 To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp install job.yaml # job file is attached in this email bin/lkp run job.yaml Thanks, Rong Chen