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| author |   Alexei Starovoitov <ast@kernel.org> | 2024-04-26 17:25:44 -0700 |
|---|---|---|
| committer |   Martin KaFai Lau <martin.lau@kernel.org> | 2024-04-29 14:16:41 -0700 |
| commit | 0db63c0b86e981a1e97d2596d64ceceba1a5470e (patch) | |
| tree | d7e6ddaca356bbd5069fe7a5a8aab2cfa0fe97d7 /tools | |
| parent | Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next (diff) | |
| download | wireguard-linux-0db63c0b86e981a1e97d2596d64ceceba1a5470e.tar.xz wireguard-linux-0db63c0b86e981a1e97d2596d64ceceba1a5470e.zip | |
bpf: Fix verifier assumptions about socket->sk
The verifier assumes that 'sk' field in 'struct socket' is valid
and non-NULL when 'socket' pointer itself is trusted and non-NULL.
That may not be the case when socket was just created and
passed to LSM socket_accept hook.
Fix this verifier assumption and adjust tests.
Reported-by: Liam Wisehart <liamwisehart@meta.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 6fcd486b3a0a ("bpf: Refactor RCU enforcement in the verifier.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240427002544.68803-1-alexei.starovoitov@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/bench_local_storage_create.c | 5 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/local_storage.c | 20 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/lsm_cgroup.c | 8 |
3 files changed, 20 insertions, 13 deletions
diff --git a/tools/testing/selftests/bpf/progs/bench_local_storage_create.c b/tools/testing/selftests/bpf/progs/bench_local_storage_create.c index e4bfbba6c193..c8ec0d0368e4 100644 --- a/tools/testing/selftests/bpf/progs/bench_local_storage_create.c +++ b/tools/testing/selftests/bpf/progs/bench_local_storage_create.c @@ -61,14 +61,15 @@ SEC("lsm.s/socket_post_create") int BPF_PROG(socket_post_create, struct socket *sock, int family, int type, int protocol, int kern) { + struct sock *sk = sock->sk; struct storage *stg; __u32 pid; pid = bpf_get_current_pid_tgid() >> 32; - if (pid != bench_pid) + if (pid != bench_pid || !sk) return 0; - stg = bpf_sk_storage_get(&sk_storage_map, sock->sk, NULL, + stg = bpf_sk_storage_get(&sk_storage_map, sk, NULL, BPF_LOCAL_STORAGE_GET_F_CREATE); if (stg) diff --git a/tools/testing/selftests/bpf/progs/local_storage.c b/tools/testing/selftests/bpf/progs/local_storage.c index e5e3a8b8dd07..637e75df2e14 100644 --- a/tools/testing/selftests/bpf/progs/local_storage.c +++ b/tools/testing/selftests/bpf/progs/local_storage.c @@ -140,11 +140,12 @@ int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, { __u32 pid = bpf_get_current_pid_tgid() >> 32; struct local_storage *storage; + struct sock *sk = sock->sk; - if (pid != monitored_pid) + if (pid != monitored_pid || !sk) return 0; - storage = bpf_sk_storage_get(&sk_storage_map, sock->sk, 0, 0); + storage = bpf_sk_storage_get(&sk_storage_map, sk, 0, 0); if (!storage) return 0; @@ -155,24 +156,24 @@ int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, /* This tests that we can associate multiple elements * with the local storage. */ - storage = bpf_sk_storage_get(&sk_storage_map2, sock->sk, 0, + storage = bpf_sk_storage_get(&sk_storage_map2, sk, 0, BPF_LOCAL_STORAGE_GET_F_CREATE); if (!storage) return 0; - if (bpf_sk_storage_delete(&sk_storage_map2, sock->sk)) + if (bpf_sk_storage_delete(&sk_storage_map2, sk)) return 0; - storage = bpf_sk_storage_get(&sk_storage_map2, sock->sk, 0, + storage = bpf_sk_storage_get(&sk_storage_map2, sk, 0, BPF_LOCAL_STORAGE_GET_F_CREATE); if (!storage) return 0; - if (bpf_sk_storage_delete(&sk_storage_map, sock->sk)) + if (bpf_sk_storage_delete(&sk_storage_map, sk)) return 0; /* Ensure that the sk_storage_map is disconnected from the storage. */ - if (!sock->sk->sk_bpf_storage || sock->sk->sk_bpf_storage->smap) + if (!sk->sk_bpf_storage || sk->sk_bpf_storage->smap) return 0; sk_storage_result = 0; @@ -185,11 +186,12 @@ int BPF_PROG(socket_post_create, struct socket *sock, int family, int type, { __u32 pid = bpf_get_current_pid_tgid() >> 32; struct local_storage *storage; + struct sock *sk = sock->sk; - if (pid != monitored_pid) + if (pid != monitored_pid || !sk) return 0; - storage = bpf_sk_storage_get(&sk_storage_map, sock->sk, 0, + storage = bpf_sk_storage_get(&sk_storage_map, sk, 0, BPF_LOCAL_STORAGE_GET_F_CREATE); if (!storage) return 0; diff --git a/tools/testing/selftests/bpf/progs/lsm_cgroup.c b/tools/testing/selftests/bpf/progs/lsm_cgroup.c index 02c11d16b692..d7598538aa2d 100644 --- a/tools/testing/selftests/bpf/progs/lsm_cgroup.c +++ b/tools/testing/selftests/bpf/progs/lsm_cgroup.c @@ -103,11 +103,15 @@ static __always_inline int real_bind(struct socket *sock, int addrlen) { struct sockaddr_ll sa = {}; + struct sock *sk = sock->sk; - if (sock->sk->__sk_common.skc_family != AF_PACKET) + if (!sk) + return 1; + + if (sk->__sk_common.skc_family != AF_PACKET) return 1; - if (sock->sk->sk_kern_sock) + if (sk->sk_kern_sock) return 1; bpf_probe_read_kernel(&sa, sizeof(sa), address); |