From patchwork Mon Mar 25 09:56:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 13601831 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9B87A18AFC5; Mon, 25 Mar 2024 09:52:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711360381; cv=none; b=EpjLRKR2cOqIr7Qq8of6OJ42+aAJQ9CBLF3WLPAtKXk9LB7v/y9GNQHoLDGpYkafCB2Bp4AMN+MZLIzJvWuMmnmrfQ9VIlaMUr2euV5GsWVm3nnDteEAmglWa5+B0S69E8PmfTNsa7oEKGT4JOEEu3q7dspRiibVUVy2ibw8CjI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711360381; c=relaxed/simple; bh=iilZid+oT+pGEFAMunYNcrjmdyzHWWGlHCwE6zHW9lo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=acQBBbc614Vce7eOi0VVRiRimyvahxbUhcd8JRID573sDzGkXlX/yQzzLipuKd3rDvBCifGYeYQNt6pIb9ZfD9TyjwEqeh5843YKvQsS6YFTZq10IZtQGp/5UOZD+5Znb0Ne1UjfWiha94M74FCD51y4/t9v0+vvb5t4oHjpYdU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4V37XN41mVz4f3kq9; Mon, 25 Mar 2024 17:52:52 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.252]) by mail.maildlp.com (Postfix) with ESMTP id 8ECCA1A017C; Mon, 25 Mar 2024 17:52:56 +0800 (CST) Received: from k01.huawei.com (unknown [10.67.174.197]) by APP3 (Coremail) with SMTP id _Ch0CgDn9Jx1SQFmHl6fHw--.8953S5; Mon, 25 Mar 2024 17:52:56 +0800 (CST) From: Xu Kuohai To: bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Florent Revest , Brendan Jackman , Paul Moore , James Morris , "Serge E . Hallyn" , Khadija Kamran , Casey Schaufler , Ondrej Mosnacek , Kees Cook , John Johansen , Lukas Bulwahn , Roberto Sassu , Shung-Hsi Yu Subject: [PATCH bpf-next v2 3/7] bpf, lsm: Add function to read lsm hook return value range Date: Mon, 25 Mar 2024 17:56:49 +0800 Message-Id: <20240325095653.1720123-4-xukuohai@huaweicloud.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240325095653.1720123-1-xukuohai@huaweicloud.com> References: <20240325095653.1720123-1-xukuohai@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: _Ch0CgDn9Jx1SQFmHl6fHw--.8953S5 X-Coremail-Antispam: 1UD129KBjvJXoWxCF45Zw1kGr1DuF45WFyDZFb_yoW5Kw45pF sxAa1Yyrs8Aw43KF1ayF4rA3W3Xr1vq3yUGFy7Gry2ya1Syw1kXa1DGrn8tr9xurWvkw15 CF4jg3yfC347ZaDanT9S1TB71UUUUUJqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP0b4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2kKe7AKxVWUXVWUAwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0V AKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1l Ox8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04 v7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_ Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXwCIc40Y0x 0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8 Jr0_Cr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJw CI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7IU1GXdUUU UUU== X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ X-Patchwork-Delegate: bpf@iogearbox.net From: Xu Kuohai Add function to read lsm hook return value range. The following patch will use this information to check lsm hook return values in bpf verifier. Signed-off-by: Xu Kuohai --- include/linux/bpf_lsm.h | 8 ++++++ kernel/bpf/bpf_lsm.c | 56 ++++++++++++++++++++++++++++++++++++++++- 2 files changed, 63 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 #include +#include #include #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..7b4611fd3a37 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include #include @@ -40,6 +39,31 @@ 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_ERRNO -MAX_ERRNO, 0 +#define LSM_RET_INT_ANY INT_MIN, INT_MAX +#define LSM_RET_INT(defval, range_desc) LSM_RET_INT_##range_desc + +#define LSM_HOOK_RETVAL_int(NAME, ...) \ +{ (unsigned long)&bpf_lsm_##NAME, __VA_ARGS__ }, + +#define LSM_HOOK_RETVAL_void(NAME, ...) + +#define LSM_HOOK(RET, DEFAULT, NAME, ...) \ +LSM_HOOK_RETVAL_##RET(NAME, DEFAULT) + +static struct lsm_retval_desc lsm_retvalues[] = { +#include +}; +#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 @@ -399,3 +423,33 @@ 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; +}