diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2023-05-23 02:29:14 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-05-23 17:56:37 +0300 |
| commit | e7d85427ef898afe66c4c1b7e06e5659cec6b640 (patch) | |
| tree | b01e23b47266421525dd69c2bc2fce34c35ac448 /kernel/bpf | |
| parent | f46392ee3dec24066e5fb260d9bd497b4cd4d191 (diff) | |
| download | linux-e7d85427ef898afe66c4c1b7e06e5659cec6b640.tar.xz | |
bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
Do a sanity check whether provided file-to-be-pinned is actually a BPF
object (prog, map, btf) before calling security_path_mknod LSM hook. If
it's not, LSM hook doesn't have to be triggered, as the operation has no
chance of succeeding anyways.
Suggested-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/bpf/20230522232917.2454595-2-andrii@kernel.org
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/inode.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index 9948b542a470..329f27d5cacf 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -448,18 +448,17 @@ static int bpf_obj_do_pin(const char __user *pathname, void *raw, if (IS_ERR(dentry)) return PTR_ERR(dentry); - mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask()); - - ret = security_path_mknod(&path, dentry, mode, 0); - if (ret) - goto out; - dir = d_inode(path.dentry); if (dir->i_op != &bpf_dir_iops) { ret = -EPERM; goto out; } + mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask()); + ret = security_path_mknod(&path, dentry, mode, 0); + if (ret) + goto out; + switch (type) { case BPF_TYPE_PROG: ret = vfs_mkobj(dentry, mode, bpf_mkprog, raw); |