diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2020-08-31 13:16:51 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-08-31 23:03:57 +0200 |
| commit | f56407fa6e69499a06bf1e0543fa93be6922acba (patch) | |
| tree | 4bee8de2bdfd2f3caa3c4499c54b9196129c6525 /tools/testing | |
| parent | b69e56cf765155dcac0037d7d0f162a2afab76c2 (diff) | |
bpf: Remove bpf_lsm_file_mprotect from sleepable list.
Technically the bpf programs can sleep while attached to bpf_lsm_file_mprotect,
but such programs need to access user memory. So they're in might_fault()
category. Which means they cannot be called from file_mprotect lsm hook that
takes write lock on mm->mmap_lock.
Adjust the test accordingly.
Also add might_fault() to __bpf_prog_enter_sleepable() to catch such deadlocks early.
Fixes: 1e6c62a88215 ("bpf: Introduce sleepable BPF programs")
Fixes: e68a144547fc ("selftests/bpf: Add sleepable tests")
Reported-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200831201651.82447-1-alexei.starovoitov@gmail.com
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/lsm.c | 34 |
1 files changed, 17 insertions, 17 deletions
diff --git a/tools/testing/selftests/bpf/progs/lsm.c b/tools/testing/selftests/bpf/progs/lsm.c index 49fa6ca99755..ff4d343b94b5 100644 --- a/tools/testing/selftests/bpf/progs/lsm.c +++ b/tools/testing/selftests/bpf/progs/lsm.c @@ -36,14 +36,10 @@ int monitored_pid = 0; int mprotect_count = 0; int bprm_count = 0; -SEC("lsm.s/file_mprotect") +SEC("lsm/file_mprotect") int BPF_PROG(test_int_hook, struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot, int ret) { - char args[64]; - __u32 key = 0; - __u64 *value; - if (ret != 0) return ret; @@ -53,18 +49,6 @@ int BPF_PROG(test_int_hook, struct vm_area_struct *vma, is_stack = (vma->vm_start <= vma->vm_mm->start_stack && vma->vm_end >= vma->vm_mm->start_stack); - bpf_copy_from_user(args, sizeof(args), (void *)vma->vm_mm->arg_start); - - value = bpf_map_lookup_elem(&array, &key); - if (value) - *value = 0; - value = bpf_map_lookup_elem(&hash, &key); - if (value) - *value = 0; - value = bpf_map_lookup_elem(&lru_hash, &key); - if (value) - *value = 0; - if (is_stack && monitored_pid == pid) { mprotect_count++; ret = -EPERM; @@ -77,10 +61,26 @@ SEC("lsm.s/bprm_committed_creds") int BPF_PROG(test_void_hook, struct linux_binprm *bprm) { __u32 pid = bpf_get_current_pid_tgid() >> 32; + char args[64]; + __u32 key = 0; + __u64 *value; if (monitored_pid == pid) bprm_count++; + bpf_copy_from_user(args, sizeof(args), (void *)bprm->vma->vm_mm->arg_start); + bpf_copy_from_user(args, sizeof(args), (void *)bprm->mm->arg_start); + + value = bpf_map_lookup_elem(&array, &key); + if (value) + *value = 0; + value = bpf_map_lookup_elem(&hash, &key); + if (value) + *value = 0; + value = bpf_map_lookup_elem(&lru_hash, &key); + if (value) + *value = 0; + return 0; } SEC("lsm/task_free") /* lsm/ is ok, lsm.s/ fails */ |