From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>,
<martin.lau@kernel.org>
Cc: <cyphar@cyphar.com>, <brauner@kernel.org>,
<lennart@poettering.net>, <linux-fsdevel@vger.kernel.org>,
Andrii Nakryiko <andrii@kernel.org>
Subject: [PATCH v4 bpf-next 1/4] bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
Date: Tue, 23 May 2023 10:00:10 -0700 [thread overview]
Message-ID: <20230523170013.728457-2-andrii@kernel.org> (raw)
In-Reply-To: <20230523170013.728457-1-andrii@kernel.org>
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
---
kernel/bpf/inode.c | 11 +++++------
1 file 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);
--
2.34.1
next prev parent reply other threads:[~2023-05-23 17:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-23 17:00 [PATCH v4 bpf-next 0/4] Add O_PATH-based BPF_OBJ_PIN and BPF_OBJ_GET support Andrii Nakryiko
2023-05-23 17:00 ` Andrii Nakryiko [this message]
2023-05-23 17:00 ` [PATCH v4 bpf-next 2/4] libbpf: start v1.3 development cycle Andrii Nakryiko
2023-05-23 17:00 ` [PATCH v4 bpf-next 3/4] bpf: support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands Andrii Nakryiko
2023-05-23 17:00 ` [PATCH v4 bpf-next 4/4] selftests/bpf: add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests Andrii Nakryiko
2023-05-23 19:43 ` [PATCH v4 bpf-next 0/4] Add O_PATH-based BPF_OBJ_PIN and BPF_OBJ_GET support Daniel Borkmann
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