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-rw-r--r--security/smack/smack_lsm.c53
1 files changed, 37 insertions, 16 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b0be893ad44d..62ebf4f8a6c7 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -837,31 +837,43 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct smk_audit_info ad;
+ struct smack_known *skp;
+ int check_priv = 0;
+ int check_import = 0;
+ int check_star = 0;
int rc = 0;
+ /*
+ * Check label validity here so import won't fail in post_setxattr
+ */
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
- strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
- strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
- strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
- if (!smack_privileged(CAP_MAC_ADMIN))
- rc = -EPERM;
- /*
- * check label validity here so import wont fail on
- * post_setxattr
- */
- if (size == 0 || size >= SMK_LONGLABEL ||
- smk_import(value, size) == NULL)
- rc = -EINVAL;
+ strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
+ check_priv = 1;
+ check_import = 1;
+ } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
+ strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
+ check_priv = 1;
+ check_import = 1;
+ check_star = 1;
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
- if (!smack_privileged(CAP_MAC_ADMIN))
- rc = -EPERM;
+ check_priv = 1;
if (size != TRANS_TRUE_SIZE ||
strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
rc = -EINVAL;
} else
rc = cap_inode_setxattr(dentry, name, value, size, flags);
+ if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
+ rc = -EPERM;
+
+ if (rc == 0 && check_import) {
+ skp = smk_import_entry(value, size);
+ if (skp == NULL || (check_star &&
+ (skp == &smack_known_star || skp == &smack_known_web)))
+ rc = -EINVAL;
+ }
+
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
@@ -2847,8 +2859,17 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
if (rc >= 0)
transflag = SMK_INODE_TRANSMUTE;
}
- isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
- isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
+ /*
+ * Don't let the exec or mmap label be "*" or "@".
+ */
+ skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
+ if (skp == &smack_known_star || skp == &smack_known_web)
+ skp = NULL;
+ isp->smk_task = skp;
+ skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
+ if (skp == &smack_known_star || skp == &smack_known_web)
+ skp = NULL;
+ isp->smk_mmap = skp;
dput(dp);
break;