From patchwork Thu Jul 11 11:18:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 13730411 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 C4D66158DC8; Thu, 11 Jul 2024 11:14:00 +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=1720696443; cv=none; b=P78+g7y6tmygFHMdtmq3LMM8/oMguHKN/hzC5Ui+iFOLDCgEzg4hbRGAu8+iwJSRkqnOWINRCxnrmW3t7v/z9HuiZOpgA5AgKnv9z28tHZSYb6Iz98anPeIuPU1ALHg5ZUpAiPjjN+FCZ6D5hSpuEv/z2uwb6q3TWi+xIiDgf2I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720696443; c=relaxed/simple; bh=ShKudblWtSVIcHknjFeCbDdWn8i6PCKbPF6Ecli0nrg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TZrqEG8wRWRkR+tS0yv6MybsPPmqIx2UHVLpRkfXltvFZSuTbQAuJXmnXN37BnJmLoxL8AyQ9kwlBTJ0hymoHaRC0zIfhLpApBvggzxwGA7YV+c7QpzPMLjH7yVpJL4qOYAkaE5V4tZ+Z6UhUZtHKIDwU7Yhs1UydxYEJf0Fisk= 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 [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4WKXCs0Fv9z4f3m6t; Thu, 11 Jul 2024 19:13:45 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id E0E9D1A0568; Thu, 11 Jul 2024 19:13:57 +0800 (CST) Received: from k01.huawei.com (unknown [10.67.174.197]) by APP4 (Coremail) with SMTP id gCh0CgCHjPVxvo9mulQgBw--.25300S10; Thu, 11 Jul 2024 19:13:57 +0800 (CST) From: Xu Kuohai To: bpf@vger.kernel.org, netdev@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-integrity@vger.kernel.org, apparmor@lists.ubuntu.com, selinux@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Matt Bobrowski , 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 , Edward Cree , Alexander Viro , Christian Brauner , Trond Myklebust , Anna Schumaker , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Stephen Smalley Subject: [PATCH bpf-next v4 08/20] lsm: Refactor return value of LSM hook getprocattr Date: Thu, 11 Jul 2024 19:18:56 +0800 Message-Id: <20240711111908.3817636-9-xukuohai@huaweicloud.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240711111908.3817636-1-xukuohai@huaweicloud.com> References: <20240711111908.3817636-1-xukuohai@huaweicloud.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgCHjPVxvo9mulQgBw--.25300S10 X-Coremail-Antispam: 1UD129KBjvJXoW3GrWUWr4xGFyfGFyfZFy7ZFb_yoWxZw48pF s5K3ZrGrW8WFy7ZF4vyFnxCa1Sv3yrWr13J398Cw1IyFy2qw4xWa45GFyY9rWrCw1DuF1D tanFqr45Cr4DAF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBqb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2 Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s02 6x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26rWY6r4UJwCIc40Y0x0EwIxGrwCI42 IY6xIIjxv20xvE14v26r1I6r4UMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UMIIF 0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87 Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7IU13l1DUUUUU== X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ X-Patchwork-Delegate: bpf@iogearbox.net From: Xu Kuohai To be consistent with most LSM hooks, convert the return value of hook getprocattr to 0 or a negative error code. Before: - Hook getprocattr returns length of value on success or a negative error code on failure. After: - Hook getprocattr returns 0 on success or a negative error code on failure. An output parameter @len is introduced to hold the length of value on success. Signed-off-by: Xu Kuohai --- fs/proc/base.c | 5 ++++- include/linux/lsm_hook_defs.h | 2 +- include/linux/security.h | 5 +++-- security/apparmor/lsm.c | 7 +++++-- security/security.c | 8 +++++--- security/selinux/hooks.c | 16 +++++++++------- security/smack/smack_lsm.c | 11 ++++++----- 7 files changed, 33 insertions(+), 21 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 9e1cf6cc674d..516a00f6ce36 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2721,13 +2721,16 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, char *p = NULL; ssize_t length; struct task_struct *task = get_proc_task(inode); + u32 n; if (!task) return -ESRCH; length = security_getprocattr(task, PROC_I(inode)->op.lsmid, file->f_path.dentry->d_name.name, - &p); + &p, &n); + if (!length) + length = n; put_task_struct(task); if (length > 0) length = simple_read_from_buffer(buf, count, ppos, p, length); diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 2628514bb19c..b0e3cf3fc33f 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -286,7 +286,7 @@ LSM_HOOK(int, -EOPNOTSUPP, getselfattr, unsigned int attr, LSM_HOOK(int, -EOPNOTSUPP, setselfattr, unsigned int attr, struct lsm_ctx *ctx, u32 size, u32 flags) LSM_HOOK(int, -EINVAL, getprocattr, struct task_struct *p, const char *name, - char **value) + char **value, u32 *len) LSM_HOOK(int, -EINVAL, setprocattr, const char *name, void *value, size_t size, size_t *wbytes) LSM_HOOK(int, 0, ismaclabel, const char *name) diff --git a/include/linux/security.h b/include/linux/security.h index 1f1a9696e65d..616047030a89 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -495,7 +495,7 @@ int security_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx, int security_setselfattr(unsigned int attr, struct lsm_ctx __user *ctx, u32 size, u32 flags); int security_getprocattr(struct task_struct *p, int lsmid, const char *name, - char **value); + char **value, u32 *len); int security_setprocattr(int lsmid, const char *name, void *value, size_t size, size_t *wbytes); int security_netlink_send(struct sock *sk, struct sk_buff *skb); @@ -1435,7 +1435,8 @@ static inline int security_setselfattr(unsigned int attr, } static inline int security_getprocattr(struct task_struct *p, int lsmid, - const char *name, char **value) + const char *name, char **value, + u32 *len) { return -EINVAL; } diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 6c8b1f8c5781..0454f3f1af06 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -820,7 +820,7 @@ static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx, } static int apparmor_getprocattr(struct task_struct *task, const char *name, - char **value) + char **value, u32 *len) { int error = -ENOENT; /* released below */ @@ -843,7 +843,10 @@ static int apparmor_getprocattr(struct task_struct *task, const char *name, aa_put_label(label); put_cred(cred); - return error; + if (error < 0) + return error; + *len = error; + return 0; } static int do_setattr(u64 attr, void *value, size_t size) diff --git a/security/security.c b/security/security.c index 9685096dbf16..9dd2ae6cf763 100644 --- a/security/security.c +++ b/security/security.c @@ -4117,20 +4117,22 @@ int security_setselfattr(unsigned int attr, struct lsm_ctx __user *uctx, * @lsmid: LSM identification * @name: attribute name * @value: attribute value + * @len: length of @value * * Read attribute @name for task @p and store it into @value if allowed. * - * Return: Returns the length of @value on success, a negative value otherwise. + * Return: Returns 0 on success or a negative error code on failure. + * @len is set to the length of @value on success. */ int security_getprocattr(struct task_struct *p, int lsmid, const char *name, - char **value) + char **value, u32 *len) { struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { if (lsmid != 0 && lsmid != hp->lsmid->id) continue; - return hp->hook.getprocattr(p, name, value); + return hp->hook.getprocattr(p, name, value, len); } return LSM_RET_DEFAULT(getprocattr); } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 7a73f3710025..16cd336aab3d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6574,19 +6574,21 @@ static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx, return rc; } -static int selinux_getprocattr(struct task_struct *p, - const char *name, char **value) +static int selinux_getprocattr(struct task_struct *p, const char *name, + char **value, u32 *len) { unsigned int attr = lsm_name_to_attr(name); - int rc; + int rc = -EINVAL; if (attr) { rc = selinux_lsm_getattr(attr, p, value); - if (rc != -EOPNOTSUPP) - return rc; + if (rc == -EOPNOTSUPP) + rc = -EINVAL; } - - return -EINVAL; + if (rc < 0) + return rc; + *len = rc; + return 0; } static int selinux_setprocattr(const char *name, void *value, size_t size, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 4265f2639106..8a352bd05565 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3681,16 +3681,17 @@ static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx, * @p: the object task * @name: the name of the attribute in /proc/.../attr * @value: where to put the result + * @len: where to put the length of the result * * Places a copy of the task Smack into value * - * Returns the length of the smack label or an error code + * Returns 0 on success or a negative error code on failure. */ -static int smack_getprocattr(struct task_struct *p, const char *name, char **value) +static int smack_getprocattr(struct task_struct *p, const char *name, + char **value, u32 *len) { struct smack_known *skp = smk_of_task_struct_obj(p); char *cp; - int slen; if (strcmp(name, "current") != 0) return -EINVAL; @@ -3699,9 +3700,9 @@ static int smack_getprocattr(struct task_struct *p, const char *name, char **val if (cp == NULL) return -ENOMEM; - slen = strlen(cp); + *len = strlen(cp); *value = cp; - return slen; + return 0; } /**