[PATCH v39 18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx
From: Casey Schaufler
Date: Fri Dec 15 2023 - 17:31:14 EST
Replace the (secctx,seclen) pointer pair with a single
lsmcontext pointer to allow return of the LSM identifier
along with the context and context length. This allows
security_release_secctx() to know how to release the
context. Callers have been modified to use or save the
returned data from the new structure.
security_lsmblob_to_secctx() will now return the length value
on success instead of 0.
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: audit@xxxxxxxxxxxxxxx
Cc: netfilter-devel@xxxxxxxxxxxxxxx
Cc: Todd Kjos <tkjos@xxxxxxxxxx>
---
include/linux/lsm_hook_defs.h | 2 +-
include/linux/security.h | 5 ++---
kernel/audit.c | 9 ++++-----
kernel/auditsc.c | 17 ++++++-----------
net/netlabel/netlabel_user.c | 3 +--
security/apparmor/include/secid.h | 3 +--
security/apparmor/secid.c | 14 ++++++++------
security/security.c | 24 +++++++++++-------------
security/selinux/hooks.c | 18 +++++++++++++++---
security/smack/smack_lsm.c | 16 ++++++++++------
10 files changed, 59 insertions(+), 52 deletions(-)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 8e0155ac6697..339a4559daf8 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -275,7 +275,7 @@ LSM_HOOK(int, -EINVAL, setprocattr, const char *name, void *value, size_t size)
LSM_HOOK(int, 0, ismaclabel, const char *name)
LSM_HOOK(int, -EOPNOTSUPP, secid_to_secctx, u32 secid, struct lsmcontext *cp)
LSM_HOOK(int, -EOPNOTSUPP, lsmblob_to_secctx, struct lsmblob *blob,
- char **secdata, u32 *seclen)
+ struct lsmcontext *cp)
LSM_HOOK(int, 0, secctx_to_secid, const char *secdata, u32 seclen, u32 *secid)
LSM_HOOK(void, LSM_RET_VOID, release_secctx, struct lsmcontext *cp)
LSM_HOOK(void, LSM_RET_VOID, inode_invalidate_secctx, struct inode *inode)
diff --git a/include/linux/security.h b/include/linux/security.h
index 03b79089eaf7..2a0615a62125 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -563,8 +563,7 @@ int security_setprocattr(int lsmid, const char *name, void *value, size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
int security_secid_to_secctx(u32 secid, struct lsmcontext *cp);
-int security_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen);
+int security_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
void security_release_secctx(struct lsmcontext *cp);
void security_inode_invalidate_secctx(struct inode *inode);
@@ -1493,7 +1492,7 @@ static inline int security_secid_to_secctx(u32 secid, struct lsmcontext *cp)
}
static inline int security_lsmblob_to_secctx(struct lsmblob *blob,
- char **secdata, u32 *seclen)
+ struct lsmcontext *cp)
{
return -EOPNOTSUPP;
}
diff --git a/kernel/audit.c b/kernel/audit.c
index 47cfb6b20c3c..a93a710c980e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1462,9 +1462,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (lsmblob_is_set(&audit_sig_lsm)) {
err = security_lsmblob_to_secctx(&audit_sig_lsm,
- &lsmctx.context,
- &lsmctx.len);
- if (err)
+ &lsmctx);
+ if (err < 0)
return err;
}
sig_data_size = struct_size(sig_data, ctx, lsmctx.len);
@@ -2175,8 +2174,8 @@ int audit_log_task_context(struct audit_buffer *ab)
if (!lsmblob_is_set(&blob))
return 0;
- error = security_lsmblob_to_secctx(&blob, &ctx.context, &ctx.len);
- if (error) {
+ error = security_lsmblob_to_secctx(&blob, &ctx);
+ if (error < 0) {
if (error != -EINVAL)
goto error_path;
return 0;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 2874255f5f25..c37cc02ea4cc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1109,7 +1109,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
from_kuid(&init_user_ns, auid),
from_kuid(&init_user_ns, uid), sessionid);
if (lsmblob_is_set(blob)) {
- if (security_lsmblob_to_secctx(blob, &ctx.context, &ctx.len)) {
+ if (security_lsmblob_to_secctx(blob, &ctx) < 0) {
audit_log_format(ab, " obj=(none)");
rc = 1;
} else {
@@ -1370,7 +1370,7 @@ static void audit_log_time(struct audit_context *context, struct audit_buffer **
static void show_special(struct audit_context *context, int *call_panic)
{
- struct lsmcontext lsmcxt;
+ struct lsmcontext lsmctx;
struct audit_buffer *ab;
int i;
@@ -1393,16 +1393,12 @@ static void show_special(struct audit_context *context, int *call_panic)
from_kgid(&init_user_ns, context->ipc.gid),
context->ipc.mode);
if (lsmblob_is_set(&context->ipc.oblob)) {
- char *ctx = NULL;
- u32 len;
-
if (security_lsmblob_to_secctx(&context->ipc.oblob,
- &ctx, &len)) {
+ &lsmctx) < 0) {
*call_panic = 1;
} else {
- audit_log_format(ab, " obj=%s", ctx);
- lsmcontext_init(&lsmcxt, ctx, len, 0);
- security_release_secctx(&lsmcxt);
+ audit_log_format(ab, " obj=%s", lsmctx.context);
+ security_release_secctx(&lsmctx);
}
}
if (context->ipc.has_perm) {
@@ -1563,8 +1559,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
if (lsmblob_is_set(&n->oblob)) {
struct lsmcontext ctx;
- if (security_lsmblob_to_secctx(&n->oblob, &ctx.context,
- &ctx.len)) {
+ if (security_lsmblob_to_secctx(&n->oblob, &ctx) < 0) {
if (call_panic)
*call_panic = 2;
} else {
diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
index b9289a22b363..561e1e476a49 100644
--- a/net/netlabel/netlabel_user.c
+++ b/net/netlabel/netlabel_user.c
@@ -98,8 +98,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
audit_info->sessionid);
if (lsmblob_is_set(&audit_info->blob) &&
- security_lsmblob_to_secctx(&audit_info->blob, &ctx.context,
- &ctx.len) == 0) {
+ security_lsmblob_to_secctx(&audit_info->blob, &ctx) >= 0) {
audit_log_format(audit_buf, " subj=%s", ctx.context);
security_release_secctx(&ctx);
}
diff --git a/security/apparmor/include/secid.h b/security/apparmor/include/secid.h
index b66c2d043a02..568820a11efc 100644
--- a/security/apparmor/include/secid.h
+++ b/security/apparmor/include/secid.h
@@ -26,8 +26,7 @@ extern int apparmor_display_secid_mode;
struct aa_label *aa_secid_to_label(u32 secid);
int apparmor_secid_to_secctx(u32 secid, struct lsmcontext *cp);
-int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen);
+int apparmor_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
void apparmor_release_secctx(struct lsmcontext *cp);
diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c
index 55d6c54fe90e..c9b9a8d90afa 100644
--- a/security/apparmor/secid.c
+++ b/security/apparmor/secid.c
@@ -93,8 +93,7 @@ int apparmor_secid_to_secctx(u32 secid, struct lsmcontext *cp)
return len;
}
-int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen)
+int apparmor_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
/* TODO: cache secctx and ref count so we don't have to recreate */
struct aa_label *label;
@@ -115,8 +114,8 @@ int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
if (apparmor_display_secid_mode)
flags |= FLAG_SHOW_MODE;
- if (secdata)
- len = aa_label_asxprint(secdata, root_ns, label,
+ if (cp)
+ len = aa_label_asxprint(&cp->context, root_ns, label,
flags, GFP_ATOMIC);
else
len = aa_label_snxprint(NULL, 0, root_ns, label, flags);
@@ -124,9 +123,12 @@ int apparmor_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
if (len < 0)
return -ENOMEM;
- *seclen = len;
+ if (cp) {
+ cp->len = len;
+ cp->id = LSM_ID_APPARMOR;
+ }
- return 0;
+ return len;
}
int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
diff --git a/security/security.c b/security/security.c
index 708a26a88447..e070a6cd4089 100644
--- a/security/security.c
+++ b/security/security.c
@@ -4203,30 +4203,28 @@ EXPORT_SYMBOL(security_secid_to_secctx);
/**
* security_lsmblob_to_secctx() - Convert a lsmblob to a secctx
* @blob: lsm specific information
- * @secdata: secctx
- * @seclen: secctx length
+ * @cp: the LSM context
*
- * Convert a @blob entry to security context. If @secdata is NULL the
- * length of the result will be returned in @seclen, but no @secdata
- * will be returned. This does mean that the length could change between
- * calls to check the length and the next call which actually allocates
- * and returns the @secdata.
+ * Convert a @blob entry to security context. If @cp is NULL the
+ * length of the result will be returned, but no data will be returned.
+ * This does mean that the length could change between calls to check
+ * the length and the next call which actually allocates and returns
+ * the data.
*
- * Return: Return 0 on success, error on failure.
+ * Return: Return length of data on success, error on failure.
*/
-int security_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen)
+int security_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
struct security_hook_list *hp;
int rc;
hlist_for_each_entry(hp, &security_hook_heads.lsmblob_to_secctx, list) {
- rc = hp->hook.lsmblob_to_secctx(blob, secdata, seclen);
- if (rc != LSM_RET_DEFAULT(secid_to_secctx))
+ rc = hp->hook.lsmblob_to_secctx(blob, cp);
+ if (rc != LSM_RET_DEFAULT(lsmblob_to_secctx))
return rc;
}
- return LSM_RET_DEFAULT(secid_to_secctx);
+ return LSM_RET_DEFAULT(lsmblob_to_secctx);
}
EXPORT_SYMBOL(security_lsmblob_to_secctx);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 37b97cf81da1..d138aa692abd 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6583,16 +6583,28 @@ static int selinux_secid_to_secctx(u32 secid, struct lsmcontext *cp)
return seclen;
}
-static int selinux_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen)
+static int selinux_lsmblob_to_secctx(struct lsmblob *blob,
+ struct lsmcontext *cp)
{
u32 secid = blob->selinux.secid;
+ u32 seclen;
+ u32 ret;
/* stacking scaffolding */
if (!secid)
secid = blob->scaffold.secid;
- return security_sid_to_context(secid, secdata, seclen);
+ if (cp) {
+ cp->id = LSM_ID_SELINUX;
+ ret = security_sid_to_context(secid, &cp->context, &cp->len);
+ if (ret < 0)
+ return ret;
+ return cp->len;
+ }
+ ret = security_sid_to_context(secid, NULL, &seclen);
+ if (ret < 0)
+ return ret;
+ return seclen;
}
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d82753bc52ab..1fdd4233a9b3 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4839,19 +4839,23 @@ static int smack_secid_to_secctx(u32 secid, struct lsmcontext *cp)
*
* Exists for audit code.
*/
-static int smack_lsmblob_to_secctx(struct lsmblob *blob, char **secdata,
- u32 *seclen)
+static int smack_lsmblob_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
{
struct smack_known *skp = blob->smack.skp;
+ int len;
/* stacking scaffolding */
if (!skp && blob->scaffold.secid)
skp = smack_from_secid(blob->scaffold.secid);
- if (secdata)
- *secdata = skp->smk_known;
- *seclen = strlen(skp->smk_known);
- return 0;
+ len = strlen(skp->smk_known);
+
+ if (cp) {
+ cp->context = skp->smk_known;
+ cp->len = len;
+ cp->id = LSM_ID_SMACK;
+ }
+ return len;
}
/**
--
2.41.0