From: Kees Cook <keescook@chromium.org>
To: Casey Schaufler <casey@schaufler-ca.com>
Cc: casey.schaufler@intel.com, jmorris@namei.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org,
john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
paul@paul-moore.com, sds@tycho.nsa.gov
Subject: Re: [PATCH v3 15/24] LSM: Specify which LSM to display
Date: Sat, 22 Jun 2019 15:51:49 -0700 [thread overview]
Message-ID: <201906221551.E15AC5472D@keescook> (raw)
In-Reply-To: <20190621185233.6766-16-casey@schaufler-ca.com>
On Fri, Jun 21, 2019 at 11:52:24AM -0700, Casey Schaufler wrote:
> Create a new entry "display" in /proc/.../attr for controlling
> which LSM security information is displayed for a process.
> The name of an active LSM that supplies hooks for human readable
> data may be written to "display" to set the value. The name of
> the LSM currently in use can be read from "display".
> At this point there can only be one LSM capable of display
> active.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> ---
> fs/proc/base.c | 1 +
> security/security.c | 110 +++++++++++++++++++++++++++++++++++---------
> 2 files changed, 90 insertions(+), 21 deletions(-)
>
> diff --git a/fs/proc/base.c b/fs/proc/base.c
> index ddef482f1334..7bf70e041315 100644
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -2618,6 +2618,7 @@ static const struct pid_entry attr_dir_stuff[] = {
> ATTR(NULL, "fscreate", 0666),
> ATTR(NULL, "keycreate", 0666),
> ATTR(NULL, "sockcreate", 0666),
> + ATTR(NULL, "display", 0666),
> #ifdef CONFIG_SECURITY_SMACK
> DIR("smack", 0555,
> proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
> diff --git a/security/security.c b/security/security.c
> index aa8e1c73a062..92c5aa427b53 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -46,7 +46,9 @@ static struct kmem_cache *lsm_file_cache;
> static struct kmem_cache *lsm_inode_cache;
>
> char *lsm_names;
> -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
> +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = {
> + .lbs_task = sizeof(int), /* slot number for the "display" LSM */
> +};
>
> /* Boot-time LSM user choice */
> static __initdata const char *chosen_lsm_order;
> @@ -583,6 +585,8 @@ int lsm_inode_alloc(struct inode *inode)
> */
> static int lsm_task_alloc(struct task_struct *task)
> {
> + int *display;
> +
> if (blob_sizes.lbs_task == 0) {
> task->security = NULL;
> return 0;
> @@ -591,6 +595,15 @@ static int lsm_task_alloc(struct task_struct *task)
> task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL);
> if (task->security == NULL)
> return -ENOMEM;
> +
> + /*
> + * The start of the task blob contains the "display" LSM slot number.
> + * Start with it set to the invalid slot number, indicating that the
> + * default first registered LSM be displayed.
> + */
> + display = task->security;
> + *display = LSMBLOB_INVALID;
> +
> return 0;
> }
>
> @@ -1579,14 +1592,24 @@ int security_file_open(struct file *file)
>
> int security_task_alloc(struct task_struct *task, unsigned long clone_flags)
> {
> + int *odisplay = current->security;
> + int *ndisplay;
> int rc = lsm_task_alloc(task);
>
> - if (rc)
> + if (unlikely(rc))
> return rc;
> +
> rc = call_int_hook(task_alloc, 0, task, clone_flags);
> - if (unlikely(rc))
> + if (unlikely(rc)) {
> security_task_free(task);
> - return rc;
> + return rc;
> + }
> +
> + ndisplay = task->security;
> + if (ndisplay && odisplay)
> + *ndisplay = *odisplay;
> +
> + return 0;
> }
>
> void security_task_free(struct task_struct *task)
> @@ -1972,10 +1995,28 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
> char **value)
> {
> struct security_hook_list *hp;
> + int *display = current->security;
> +
> + if (!strcmp(name, "display")) {
> + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> + list) {
> + if (*display == LSMBLOB_INVALID ||
> + hp->slot == *display) {
> + *value = kstrdup(hp->lsm, GFP_KERNEL);
> + if (*value)
> + return strlen(hp->lsm);
> + return -ENOMEM;
> + }
> + }
> + return -EINVAL;
> + }
>
> hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
> if (lsm != NULL && strcmp(lsm, hp->lsm))
> continue;
> + if (lsm == NULL && *display != LSMBLOB_INVALID &&
> + *display != hp->slot)
> + continue;
> return hp->hook.getprocattr(p, name, value);
> }
> return -EINVAL;
> @@ -1985,10 +2026,27 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> size_t size)
> {
> struct security_hook_list *hp;
> + int *display = current->security;
> + int len;
> +
> + if (!strcmp(name, "display")) {
> + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx,
> + list) {
> + len = strlen(hp->lsm);
> + if (size >= len && !strncmp(value, hp->lsm, len)) {
> + *display = hp->slot;
> + return size;
> + }
> + }
> + return -EINVAL;
> + }
>
> hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
> if (lsm != NULL && strcmp(lsm, hp->lsm))
> continue;
> + if (lsm == NULL && *display != LSMBLOB_INVALID &&
> + *display != hp->slot)
> + continue;
> return hp->hook.setprocattr(name, value, size);
> }
> return -EINVAL;
> @@ -2008,14 +2066,12 @@ EXPORT_SYMBOL(security_ismaclabel);
> int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> {
> struct security_hook_list *hp;
> - int rc;
> + int *display = current->security;
>
> - hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> - rc = hp->hook.secid_to_secctx(blob->secid[hp->slot],
> - secdata, seclen);
> - if (rc != 0)
> - return rc;
> - }
> + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list)
> + if (*display == LSMBLOB_INVALID || *display == hp->slot)
> + return hp->hook.secid_to_secctx(blob->secid[hp->slot],
> + secdata, seclen);
> return 0;
> }
> EXPORT_SYMBOL(security_secid_to_secctx);
> @@ -2024,22 +2080,27 @@ int security_secctx_to_secid(const char *secdata, u32 seclen,
> struct lsmblob *blob)
> {
> struct security_hook_list *hp;
> - int rc;
> + int *display = current->security;
>
> lsmblob_init(blob, 0);
> - hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> - rc = hp->hook.secctx_to_secid(secdata, seclen,
> - &blob->secid[hp->slot]);
> - if (rc != 0)
> - return rc;
> - }
> + hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list)
> + if (*display == LSMBLOB_INVALID || *display == hp->slot)
> + return hp->hook.secctx_to_secid(secdata, seclen,
> + &blob->secid[hp->slot]);
> return 0;
> }
> EXPORT_SYMBOL(security_secctx_to_secid);
>
> void security_release_secctx(char *secdata, u32 seclen)
> {
> - call_void_hook(release_secctx, secdata, seclen);
> + struct security_hook_list *hp;
> + int *display = current->security;
> +
> + hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list)
> + if (*display == LSMBLOB_INVALID || *display == hp->slot) {
> + hp->hook.release_secctx(secdata, seclen);
> + return;
> + }
> }
> EXPORT_SYMBOL(security_release_secctx);
>
> @@ -2164,8 +2225,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb);
> int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> int __user *optlen, unsigned len)
> {
> - return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock,
> - optval, optlen, len);
> + int *display = current->security;
> + struct security_hook_list *hp;
> +
> + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream,
> + list)
> + if (*display == LSMBLOB_INVALID || *display == hp->slot)
> + return hp->hook.socket_getpeersec_stream(sock, optval,
> + optlen, len);
> + return -ENOPROTOOPT;
> }
>
> int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> --
> 2.20.1
>
--
Kees Cook
next prev parent reply other threads:[~2019-06-22 22:51 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-21 18:52 [PATCH v3 00/24] LSM: Module stacking for AppArmor Casey Schaufler
2019-06-21 18:52 ` [PATCH v3 01/24] LSM: Infrastructure management of the superblock Casey Schaufler
2019-06-24 18:31 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 02/24] LSM: Infrastructure management of the sock security Casey Schaufler
2019-06-24 18:33 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 03/24] LSM: Infrastructure management of the key blob Casey Schaufler
2019-06-24 18:33 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 04/24] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-06-22 22:42 ` Kees Cook
2019-06-24 18:38 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 05/24] Use lsmblob in security_audit_rule_match Casey Schaufler
2019-06-22 22:43 ` Kees Cook
2019-06-24 18:39 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 06/24] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-06-22 22:43 ` Kees Cook
2019-06-24 18:38 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 07/24] net: Prepare UDS for secuirty module stacking Casey Schaufler
2019-06-22 22:43 ` Kees Cook
2019-06-24 18:39 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 08/24] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2019-06-22 22:44 ` Kees Cook
2019-06-24 18:38 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 09/24] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-06-22 22:44 ` Kees Cook
2019-06-24 18:39 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 10/24] Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-06-22 22:48 ` Kees Cook
2019-06-24 16:39 ` Casey Schaufler
2019-06-24 17:20 ` Casey Schaufler
2019-06-24 21:09 ` Kees Cook
2019-06-24 18:39 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 11/24] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2019-06-22 22:49 ` Kees Cook
2019-06-24 18:40 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 12/24] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-06-22 22:49 ` Kees Cook
2019-06-24 18:40 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 13/24] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-06-22 22:50 ` Kees Cook
2019-06-24 18:40 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 14/24] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-06-22 22:51 ` Kees Cook
2019-06-24 18:40 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 15/24] LSM: Specify which LSM to display Casey Schaufler
2019-06-22 22:51 ` Kees Cook [this message]
2019-06-24 18:48 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 16/24] LSM: Ensure the correct LSM context releaser Casey Schaufler
2019-06-22 22:52 ` Kees Cook
2019-06-24 21:46 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 17/24] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2019-06-22 22:52 ` Kees Cook
2019-06-24 21:46 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 18/24] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2019-06-22 22:54 ` Kees Cook
2019-06-24 21:46 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 19/24] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-06-22 22:56 ` Kees Cook
2019-06-24 21:46 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 20/24] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2019-06-22 22:57 ` Kees Cook
2019-06-24 21:47 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 21/24] Audit: Store LSM audit information in an lsmblob Casey Schaufler
2019-06-22 23:12 ` Kees Cook
2019-06-24 21:33 ` John Johansen
2019-06-25 1:01 ` Casey Schaufler
2019-06-25 1:46 ` Paul Moore
2019-06-25 2:14 ` John Johansen
2019-06-25 2:42 ` Paul Moore
2019-06-25 15:30 ` Casey Schaufler
2019-06-21 18:52 ` [PATCH v3 22/24] LSM: Return the lsmblob slot on initialization Casey Schaufler
2019-06-22 23:13 ` Kees Cook
2019-06-24 21:39 ` John Johansen
2019-06-24 21:50 ` Kees Cook
2019-06-24 21:53 ` Casey Schaufler
2019-06-24 21:47 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 23/24] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2019-06-22 23:15 ` Kees Cook
2019-06-24 21:44 ` John Johansen
2019-06-21 18:52 ` [PATCH v3 24/24] AppArmor: Remove the exclusive flag Casey Schaufler
2019-06-22 23:15 ` Kees Cook
2019-06-24 21:45 ` John Johansen
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