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| author | Milan Landaverde <milan@mdaverde.com> | 2022-12-13 18:57:14 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-12-14 18:35:41 +0100 |
| commit | e89f3edffb860a0f54a9ed16deadb7a4a1fa3862 (patch) | |
| tree | d953d34b8c4be2f7ce66f7d34eb07f0727ac392a /kernel | |
| parent | selftests/bpf: Select CONFIG_FUNCTION_ERROR_INJECTION (diff) | |
| download | linux-e89f3edffb860a0f54a9ed16deadb7a4a1fa3862.tar.xz linux-e89f3edffb860a0f54a9ed16deadb7a4a1fa3862.zip | |
bpf: prevent leak of lsm program after failed attach
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
Diffstat (limited to 'kernel')
| -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 35972afb6850..64131f88c553 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3518,9 +3518,9 @@ 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; |