[ Upstream commit 33f339a1ba54e56bba57ee9a77c71e385ab4825c ]
There's a potential race when `cgroup_bpf_enabled(CGROUP_GETSOCKOPT)` is
false during the execution of `BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN`, but
becomes true when `BPF_CGROUP_RUN_PROG_GETSOCKOPT` is called.
This inconsistency can lead to `BPF_CGROUP_RUN_PROG_GETSOCKOPT` receiving
an "-EFAULT" from `__cgroup_bpf_run_filter_getsockopt(max_optlen=0)`.
Scenario shown as below:
`process A` `process B`
----------- ------------
BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN
enable CGROUP_GETSOCKOPT
BPF_CGROUP_RUN_PROG_GETSOCKOPT (-EFAULT)
To resolve this, remove the `BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN` macro and
directly uses `copy_from_sockptr` to ensure that `max_optlen` is always
set before `BPF_CGROUP_RUN_PROG_GETSOCKOPT` is invoked.
Fixes: 0d01da6afc ("bpf: implement getsockopt and setsockopt hooks")
Co-developed-by: Yanghui Li <yanghui.li@mediatek.com>
Signed-off-by: Yanghui Li <yanghui.li@mediatek.com>
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20240830082518.23243-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
f8d6acb19f