Add support to Smack for retrieval of the superblock parameters.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
security/smack/smack_lsm.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 0de725f88bed..0a1e88d50ad3 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -45,6 +45,7 @@
#include <linux/parser.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
+#include <linux/fsinfo.h>
#include "smack.h"
#define TRANS_TRUE "TRUE"
@@ -893,6 +894,45 @@ static int smack_sb_statfs(struct dentry *dentry)
return rc;
}
+#ifdef CONFIG_FSINFO
+/*
+ * Retrieve the Smack filesystem information, including mount parameters.
+ */
+static int smack_sb_fsinfo(struct path *path, struct fsinfo_kparams *params)
+{
+ struct superblock_smack *sp = path->dentry->d_sb->s_security;
+
+ switch (params->request) {
+ case FSINFO_ATTR_LSM_PARAMETERS: {
+ struct dentry *root = path->dentry->d_sb->s_root;
+ struct inode *inode = d_backing_inode(root);
+ struct inode_smack *isp = inode->i_security;
+
+ if (sp->smk_flags & SMK_SB_INITIALIZED)
+ return 0;
+ if (sp->smk_floor)
+ fsinfo_note_param(params, "fsfloor", sp->smk_floor->smk_known);
+ if (sp->smk_hat)
+ fsinfo_note_param(params, "fshat", sp->smk_hat->smk_known);
+ if (sp->smk_default)
+ fsinfo_note_param(params, "fsdefault", sp->smk_default->smk_known);
+
+ if (sp->smk_root) {
+ if (isp && isp->smk_flags & SMK_INODE_TRANSMUTE)
+ fsinfo_note_param(params, "fstransmute", sp->smk_root->smk_known);
+ else
+ fsinfo_note_param(params, "fsroot", sp->smk_root->smk_known);
+ }
+ return params->usage;
+ }
+
+ default:
+ return -ENODATA;
+ }
+ return 0;
+}
+#endif
+
/*
* BPRM hooks
*/
@@ -4606,6 +4646,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
+#ifdef CONFIG_FSINFO
+ LSM_HOOK_INIT(sb_fsinfo, smack_sb_fsinfo),
+#endif
LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds),
