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| author | Tejun Heo <tj@kernel.org> | 2023-03-14 22:59:49 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-03-15 00:56:20 +0100 |
| commit | b8a2e3f93d412114a1539ea97b59b3e6ed6e1f9a (patch) | |
| tree | c4255c9e3f13cbc6914cabe13e8f2296a2eb0f87 /.gitignore | |
| parent | selftests/bpf: Fix trace_virtqueue_add_sgs test issue with LLVM 17. (diff) | |
| download | linux-b8a2e3f93d412114a1539ea97b59b3e6ed6e1f9a.tar.xz linux-b8a2e3f93d412114a1539ea97b59b3e6ed6e1f9a.zip | |
cgroup: Make current_cgns_cgroup_dfl() safe to call after exit_task_namespace()
The commit 332ea1f697be ("bpf: Add bpf_cgroup_from_id() kfunc") added
bpf_cgroup_from_id() which calls current_cgns_cgroup_dfl() through
cgroup_get_from_id(). However, BPF programs may be attached to a point where
current->nsproxy has already been cleared to NULL by exit_task_namespace()
and calling bpf_cgroup_from_id() would cause an oops.
Just return the system-wide root if nsproxy has been cleared. This allows
all cgroups to be looked up after the task passed through
exit_task_namespace(), which semantically makes sense. Given that the only
way to get this behavior is through BPF programs, it seems safe but let's
see what others think.
Fixes: 332ea1f697be ("bpf: Add bpf_cgroup_from_id() kfunc")
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/ZBDuVWiFj2jiz3i8@slm.duckdns.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to '.gitignore')
0 files changed, 0 insertions, 0 deletions