[PATCH 16/25] fsinfo: Support Smack superblock parameter retrieval [ver #14]
From: David Howells <dhowells@redhat.com>
Date: 2019-06-24 14:11:25
Also in:
linux-fsdevel, lkml
Subsystem:
security subsystem, smack security module, the rest · Maintainers:
Paul Moore, James Morris, "Serge E. Hallyn", Casey Schaufler, Linus Torvalds
Add support to Smack for retrieval of the superblock parameters. Signed-off-by: David Howells <dhowells@redhat.com> --- 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),