diff options
| -rw-r--r-- | security/smack/smack_lsm.c | 53 |
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; |