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path: root/security/smack/smack_lsm.c
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Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r--security/smack/smack_lsm.c140
1 files changed, 67 insertions, 73 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b0be893ad44d..d814e35987be 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -219,8 +219,6 @@ static int smack_ptrace_traceme(struct task_struct *ptp)
* smack_syslog - Smack approval on syslog
* @type: message type
*
- * Require that the task has the floor label
- *
* Returns 0 on success, error code otherwise.
*/
static int smack_syslog(int typefrom_file)
@@ -231,7 +229,7 @@ static int smack_syslog(int typefrom_file)
if (smack_privileged(CAP_MAC_OVERRIDE))
return 0;
- if (skp != &smack_known_floor)
+ if (smack_syslog_label != NULL && smack_syslog_label != skp)
rc = -EACCES;
return rc;
@@ -341,10 +339,12 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
struct inode *inode = root->d_inode;
struct superblock_smack *sp = sb->s_security;
struct inode_smack *isp;
+ struct smack_known *skp;
char *op;
char *commap;
char *nsp;
int transmute = 0;
+ int specified = 0;
if (sp->smk_initialized)
return 0;
@@ -359,34 +359,56 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
op += strlen(SMK_FSHAT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_hat = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
op += strlen(SMK_FSFLOOR);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_floor = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSDEFAULT,
strlen(SMK_FSDEFAULT)) == 0) {
op += strlen(SMK_FSDEFAULT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_default = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
op += strlen(SMK_FSROOT);
nsp = smk_import(op, 0);
- if (nsp != NULL)
+ if (nsp != NULL) {
sp->smk_root = nsp;
+ specified = 1;
+ }
} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
op += strlen(SMK_FSTRANS);
nsp = smk_import(op, 0);
if (nsp != NULL) {
sp->smk_root = nsp;
transmute = 1;
+ specified = 1;
}
}
}
+ if (!smack_privileged(CAP_MAC_ADMIN)) {
+ /*
+ * Unprivileged mounts don't get to specify Smack values.
+ */
+ if (specified)
+ return -EPERM;
+ /*
+ * Unprivileged mounts get root and default from the caller.
+ */
+ skp = smk_of_current();
+ sp->smk_root = skp->smk_known;
+ sp->smk_default = skp->smk_known;
+ }
/*
* Initialize the root inode.
*/
@@ -423,53 +445,6 @@ static int smack_sb_statfs(struct dentry *dentry)
return rc;
}
-/**
- * smack_sb_mount - Smack check for mounting
- * @dev_name: unused
- * @path: mount point
- * @type: unused
- * @flags: unused
- * @data: unused
- *
- * Returns 0 if current can write the floor of the filesystem
- * being mounted on, an error code otherwise.
- */
-static int smack_sb_mount(const char *dev_name, struct path *path,
- const char *type, unsigned long flags, void *data)
-{
- struct superblock_smack *sbp = path->dentry->d_sb->s_security;
- struct smk_audit_info ad;
-
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, *path);
-
- return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
-}
-
-/**
- * smack_sb_umount - Smack check for unmounting
- * @mnt: file system to unmount
- * @flags: unused
- *
- * Returns 0 if current can write the floor of the filesystem
- * being unmounted, an error code otherwise.
- */
-static int smack_sb_umount(struct vfsmount *mnt, int flags)
-{
- struct superblock_smack *sbp;
- struct smk_audit_info ad;
- struct path path;
-
- path.dentry = mnt->mnt_root;
- path.mnt = mnt;
-
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, path);
-
- sbp = path.dentry->d_sb->s_security;
- return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
-}
-
/*
* BPRM hooks
*/
@@ -837,31 +812,43 @@ 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);
@@ -1364,7 +1351,7 @@ static int smack_file_receive(struct file *file)
int may = 0;
struct smk_audit_info ad;
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
+ smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
/*
* This code relies on bitmasks.
@@ -2847,8 +2834,17 @@ 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;
@@ -3743,8 +3739,6 @@ struct security_operations smack_ops = {
.sb_copy_data = smack_sb_copy_data,
.sb_kern_mount = smack_sb_kern_mount,
.sb_statfs = smack_sb_statfs,
- .sb_mount = smack_sb_mount,
- .sb_umount = smack_sb_umount,
.bprm_set_creds = smack_bprm_set_creds,
.bprm_committing_creds = smack_bprm_committing_creds,
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-01 11:15:19 +0000