On Jun 27, 2025, at 8:59 AM, Alexei Starovoitov [off-list ref] wrote:

On Thu, Jun 26, 2025 at 9:04 PM Song Liu [off-list ref] wrote:

quoted

On Thu, Jun 26, 2025 at 7:14 PM Alexei Starovoitov
[off-list ref] wrote:
[...]

quoted

./test_progs -t lsm_cgroup
Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t lsm_cgroup
Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t cgroup_xattr
Summary: 1/8 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t lsm_cgroup
test_lsm_cgroup_functional:PASS:bind(ETH_P_ALL) 0 nsec
(network_helpers.c:121: errno: Cannot assign requested address) Failed
to bind socket
test_lsm_cgroup_functional:FAIL:start_server unexpected start_server:
actual -1 < expected 0
(network_helpers.c:360: errno: Bad file descriptor) getsockopt(SOL_PROTOCOL)
test_lsm_cgroup_functional:FAIL:connect_to_fd unexpected
connect_to_fd: actual -1 < expected 0
test_lsm_cgroup_functional:FAIL:accept unexpected accept: actual -1 < expected 0
test_lsm_cgroup_functional:FAIL:getsockopt unexpected getsockopt:
actual -1 < expected 0
test_lsm_cgroup_functional:FAIL:sk_priority unexpected sk_priority:
actual 0 != expected 234
...
Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED


Song,
Please follow up with the fix for selftest.
It will be in bpf-next only.

The issue is because cgroup_xattr calls "ip link set dev lo up"
in setup, and calls "ip link set dev lo down" in cleanup. Most
other tests only call "ip link set dev lo up". IOW, it appears to
me that cgroup_xattr is doing the cleanup properly. To fix this,
we can either remove "dev lo down" from cgroup_xattr, or add
"dev lo up" to lsm_cgroups. Do you have any preference one
way or another?

It messes with "lo" without switching netns? Ouch.

Ah, I see the problem now. 

Not sure what tests you copied that code from,
but all "ip" commands, ping_group_range, and sockets
don't need to be in the test. Instead of triggering
progs through lsm/socket_connect hook can't you use
a simple hook like lsm/bpf or lsm/file_open that doesn't require
networking setup ?

Yeah, let me fix the test with a different hook. 

Thanks,
Song