Hi Daniel,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   b229b6ca5abbd63ff40c1396095b1b36b18139c3
commit: e2d75e954c0a277b8fa0ddf666ddd4f9b73195f7 selftests/bpf: Add tests for writing to nf_conn:mark
date:   7 weeks ago
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce:
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e2d75e954c0a277b8fa0ddf666ddd4f9b73195f7
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout e2d75e954c0a277b8fa0ddf666ddd4f9b73195f7
        make O=/tmp/kselftest headers
        make O=/tmp/kselftest -C tools/testing/selftests

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> progs/test_bpf_nf_fail.c:82:4: error: incomplete definition of type 'struct nf_conn'
           ct->status = 0xF00;
           ~~^
   progs/test_bpf_nf_fail.c:7:8: note: forward declaration of 'struct nf_conn'
   struct nf_conn;
          ^
   1 error generated.

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp