diff options
| author | Milan Landaverde <milan@mdaverde.com> | 2022-12-13 12:57:14 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-31 13:26:37 +0100 |
| commit | 82b39df5ddb298daaf6dc504032ff7eb027fa106 (patch) | |
| tree | c6eeb5d1f252a71f69760b0ab31dc732b1c8a09e | |
| parent | 4d9bceb766e21d74fb249ffa8eea4e4e0de60310 (diff) | |
bpf: prevent leak of lsm program after failed attach
[ Upstream commit e89f3edffb860a0f54a9ed16deadb7a4a1fa3862 ]
In [0], we added the ability to bpf_prog_attach LSM programs to cgroups,
but in our validation to make sure the prog is meant to be attached to
BPF_LSM_CGROUP, we return too early if the check fails. This results in
lack of decrementing prog's refcnt (through bpf_prog_put)
leaving the LSM program alive past the point of the expected lifecycle.
This fix allows for the decrement to take place.
[0] https://lore.kernel.org/all/20220628174314.1216643-4-sdf@google.com/
Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor")
Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221213175714.31963-1-milan@mdaverde.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/bpf/syscall.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0e758911d963f..6b6fb7237ebea 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3505,9 +3505,9 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_PROG_TYPE_LSM: if (ptype == BPF_PROG_TYPE_LSM && prog->expected_attach_type != BPF_LSM_CGROUP) - return -EINVAL; - - ret = cgroup_bpf_prog_attach(attr, ptype, prog); + ret = -EINVAL; + else + ret = cgroup_bpf_prog_attach(attr, ptype, prog); break; default: ret = -EINVAL; |