From: Xu Kuohai <xukuohai@huaweicloud.com>
To: bpf@vger.kernel.org, netdev@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kselftest@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>,
Matt Bobrowski <mattbobrowski@google.com>,
Brendan Jackman <jackmanb@chromium.org>,
Paul Moore <paul@paul-moore.com>,
James Morris <jmorris@namei.org>,
"Serge E . Hallyn" <serge@hallyn.com>,
Khadija Kamran <kamrankhadijadj@gmail.com>,
Casey Schaufler <casey@schaufler-ca.com>,
Ondrej Mosnacek <omosnace@redhat.com>,
Kees Cook <keescook@chromium.org>,
John Johansen <john.johansen@canonical.com>,
Lukas Bulwahn <lukas.bulwahn@gmail.com>,
Roberto Sassu <roberto.sassu@huawei.com>,
Shung-Hsi Yu <shung-hsi.yu@suse.com>
Subject: [PATCH bpf-next v3 02/11] bpf, lsm: Add helper to read lsm hook return value range
Date: Thu, 11 Apr 2024 20:27:43 +0800 [thread overview]
Message-ID: <20240411122752.2873562-3-xukuohai@huaweicloud.com> (raw)
In-Reply-To: <20240411122752.2873562-1-xukuohai@huaweicloud.com>
From: Xu Kuohai <xukuohai@huawei.com>
Add helper to read lsm hook return value range. The following patch
will use this information to verify lsm hook return values in bpf
verifier.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
---
include/linux/bpf_lsm.h | 8 ++++++
kernel/bpf/bpf_lsm.c | 54 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 61 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf_lsm.h b/include/linux/bpf_lsm.h
index 1de7ece5d36d..e51c042abf43 100644
--- a/include/linux/bpf_lsm.h
+++ b/include/linux/bpf_lsm.h
@@ -9,6 +9,7 @@
#include <linux/sched.h>
#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
#include <linux/lsm_hooks.h>
#ifdef CONFIG_BPF_LSM
@@ -45,6 +46,8 @@ void bpf_inode_storage_free(struct inode *inode);
void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog, bpf_func_t *bpf_func);
+int bpf_lsm_get_retval_range(const struct bpf_prog *prog,
+ struct bpf_retval_range *range);
#else /* !CONFIG_BPF_LSM */
static inline bool bpf_lsm_is_sleepable_hook(u32 btf_id)
@@ -78,6 +81,11 @@ static inline void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog,
{
}
+static inline int bpf_lsm_get_retval_range(const struct bpf_prog *prog,
+ struct bpf_retval_range *range)
+{
+ return -EOPNOTSUPP;
+}
#endif /* CONFIG_BPF_LSM */
#endif /* _LINUX_BPF_LSM_H */
diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index ee9d1a795334..4e1a4a333000 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -11,7 +11,6 @@
#include <linux/lsm_hooks.h>
#include <linux/bpf_lsm.h>
#include <linux/kallsyms.h>
-#include <linux/bpf_verifier.h>
#include <net/bpf_sk_storage.h>
#include <linux/bpf_local_storage.h>
#include <linux/btf_ids.h>
@@ -40,6 +39,29 @@ noinline RET bpf_lsm_##NAME(__VA_ARGS__) \
#undef LSM_RET_INT
#undef LSM_RET_VOID
+struct lsm_retval_desc {
+ unsigned long func_addr;
+ int minval;
+ int maxval;
+};
+
+#define LSM_RET_INT(defval, min, max) min, max
+
+#define LSM_HOOK_RETVAL_int(NAME, ...) \
+{ (unsigned long)&bpf_lsm_##NAME, __VA_ARGS__ },
+
+#define LSM_HOOK_RETVAL_void(NAME, ...)
+
+#define LSM_HOOK(RET, RET_DESCRIPTION, NAME, ...) \
+LSM_HOOK_RETVAL_##RET(NAME, RET_DESCRIPTION)
+
+static struct lsm_retval_desc lsm_retvalues[] = {
+#include <linux/lsm_hook_defs.h>
+};
+#undef LSM_HOOK
+#undef LSM_RET_INT
+#undef LSM_RET_VOID
+
#define LSM_HOOK(RET, DEFAULT, NAME, ...) BTF_ID(func, bpf_lsm_##NAME)
BTF_SET_START(bpf_lsm_hooks)
#include <linux/lsm_hook_defs.h>
@@ -399,3 +421,33 @@ const struct bpf_verifier_ops lsm_verifier_ops = {
.get_func_proto = bpf_lsm_func_proto,
.is_valid_access = btf_ctx_access,
};
+
+static struct lsm_retval_desc *find_retval_desc(const char *func_name)
+{
+ unsigned long addr;
+ struct lsm_retval_desc *desc;
+
+ addr = kallsyms_lookup_name(func_name);
+ for (unsigned int i = 0U; i < ARRAY_SIZE(lsm_retvalues); i++) {
+ desc = &lsm_retvalues[i];
+ if (addr == desc->func_addr)
+ return desc;
+ }
+
+ return NULL;
+}
+
+int bpf_lsm_get_retval_range(const struct bpf_prog *prog,
+ struct bpf_retval_range *retval_range)
+{
+ struct lsm_retval_desc *desc;
+
+ desc = find_retval_desc(prog->aux->attach_func_name);
+ if (desc == NULL)
+ return -ENODEV;
+
+ retval_range->minval = desc->minval;
+ retval_range->maxval = desc->maxval;
+
+ return 0;
+}
--
2.30.2
next prev parent reply other threads:[~2024-04-11 12:24 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-11 12:27 [PATCH bpf-next v3 00/11] Add check for bpf lsm return value Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 01/11] bpf, lsm: Annotate lsm hook return value range Xu Kuohai
2024-04-11 12:27 ` Xu Kuohai [this message]
2024-04-11 12:27 ` [PATCH bpf-next v3 03/11] bpf, lsm: Check bpf lsm hook return values in verifier Xu Kuohai
2024-04-13 11:44 ` Eduard Zingerman
2024-04-11 12:27 ` [PATCH bpf-next v3 04/11] bpf, lsm: Add bpf lsm disabled hook list Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 05/11] bpf: Avoid progs for different hooks calling each other with tail call Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 06/11] bpf: Fix compare error in function retval_range_within Xu Kuohai
2024-04-12 8:53 ` Shung-Hsi Yu
2024-04-25 23:41 ` Andrii Nakryiko
2024-04-26 8:08 ` Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 07/11] bpf: Fix a false rejection caused by AND operation Xu Kuohai
2024-04-19 23:00 ` Eduard Zingerman
2024-04-20 8:33 ` Xu Kuohai
2024-04-23 21:55 ` Yonghong Song
2024-04-24 2:25 ` Xu Kuohai
2024-04-24 22:06 ` Yonghong Song
2024-04-25 2:42 ` Xu Kuohai
2024-04-25 16:28 ` Yonghong Song
2024-04-26 7:43 ` Xu Kuohai
2024-04-26 20:36 ` Andrii Nakryiko
2024-04-28 15:15 ` Xu Kuohai
2024-04-29 20:58 ` Andrii Nakryiko
2024-04-29 22:18 ` Eduard Zingerman
2024-04-30 3:56 ` Xu Kuohai
2024-04-30 3:54 ` Xu Kuohai
2024-04-29 21:56 ` Eduard Zingerman
2024-04-11 12:27 ` [PATCH bpf-next v3 08/11] selftests/bpf: Avoid load failure for token_lsm.c Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 09/11] selftests/bpf: Add return value checks for failed tests Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 10/11] selftests/bpf: Add test for lsm tail call Xu Kuohai
2024-04-11 12:27 ` [PATCH bpf-next v3 11/11] selftests/bpf: Add verifier tests for bpf lsm Xu Kuohai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240411122752.2873562-3-xukuohai@huaweicloud.com \
--to=xukuohai@huaweicloud.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=casey@schaufler-ca.com \
--cc=daniel@iogearbox.net \
--cc=eddyz87@gmail.com \
--cc=haoluo@google.com \
--cc=jackmanb@chromium.org \
--cc=jmorris@namei.org \
--cc=john.fastabend@gmail.com \
--cc=john.johansen@canonical.com \
--cc=jolsa@kernel.org \
--cc=kamrankhadijadj@gmail.com \
--cc=keescook@chromium.org \
--cc=kpsingh@kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=lukas.bulwahn@gmail.com \
--cc=martin.lau@linux.dev \
--cc=mattbobrowski@google.com \
--cc=netdev@vger.kernel.org \
--cc=omosnace@redhat.com \
--cc=paul@paul-moore.com \
--cc=roberto.sassu@huawei.com \
--cc=sdf@google.com \
--cc=serge@hallyn.com \
--cc=shung-hsi.yu@suse.com \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).