diff options
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 270 |
1 files changed, 181 insertions, 89 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index b9c5e149903..e8af5b0ba80 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -5,12 +5,13 @@ * * Authors: * Casey Schaufler <casey@schaufler-ca.com> - * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com> + * Jarkko Sakkinen <jarkko.sakkinen@intel.com> * * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. * Paul Moore <paul@paul-moore.com> * Copyright (C) 2010 Nokia Corporation + * Copyright (C) 2011 Intel Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, @@ -34,6 +35,7 @@ #include <linux/audit.h> #include <linux/magic.h> #include <linux/dcache.h> +#include <linux/personality.h> #include "smack.h" #define task_security(task) (task_cred_xxx((task), security)) @@ -404,7 +406,7 @@ static int smack_sb_statfs(struct dentry *dentry) static int smack_sb_mount(char *dev_name, struct path *path, char *type, unsigned long flags, void *data) { - struct superblock_smack *sbp = path->mnt->mnt_sb->s_security; + struct superblock_smack *sbp = path->dentry->d_sb->s_security; struct smk_audit_info ad; smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); @@ -433,7 +435,7 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags) smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); smk_ad_setfield_u_fs_path(&ad, path); - sbp = mnt->mnt_sb->s_security; + sbp = path.dentry->d_sb->s_security; return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad); } @@ -441,11 +443,17 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags) * BPRM hooks */ +/** + * smack_bprm_set_creds - set creds for exec + * @bprm: the exec information + * + * Returns 0 if it gets a blob, -ENOMEM otherwise + */ static int smack_bprm_set_creds(struct linux_binprm *bprm) { - struct task_smack *tsp = bprm->cred->security; + struct inode *inode = bprm->file->f_path.dentry->d_inode; + struct task_smack *bsp = bprm->cred->security; struct inode_smack *isp; - struct dentry *dp; int rc; rc = cap_bprm_set_creds(bprm); @@ -455,20 +463,48 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm) if (bprm->cred_prepared) return 0; - if (bprm->file == NULL || bprm->file->f_dentry == NULL) + isp = inode->i_security; + if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) return 0; - dp = bprm->file->f_dentry; + if (bprm->unsafe) + return -EPERM; - if (dp->d_inode == NULL) - return 0; + bsp->smk_task = isp->smk_task; + bprm->per_clear |= PER_CLEAR_ON_SETID; - isp = dp->d_inode->i_security; + return 0; +} - if (isp->smk_task != NULL) - tsp->smk_task = isp->smk_task; +/** + * smack_bprm_committing_creds - Prepare to install the new credentials + * from bprm. + * + * @bprm: binprm for exec + */ +static void smack_bprm_committing_creds(struct linux_binprm *bprm) +{ + struct task_smack *bsp = bprm->cred->security; - return 0; + if (bsp->smk_task != bsp->smk_forked) + current->pdeath_signal = 0; +} + +/** + * smack_bprm_secureexec - Return the decision to use secureexec. + * @bprm: binprm for exec + * + * Returns 0 on success. + */ +static int smack_bprm_secureexec(struct linux_binprm *bprm) +{ + struct task_smack *tsp = current_security(); + int ret = cap_bprm_secureexec(bprm); + + if (!ret && (tsp->smk_task != tsp->smk_forked)) + ret = 1; + + return ret; } /* @@ -516,6 +552,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, const struct qstr *qstr, char **name, void **value, size_t *len) { + struct smack_known *skp; + char *csp = smk_of_current(); char *isp = smk_of_inode(inode); char *dsp = smk_of_inode(dir); int may; @@ -527,8 +565,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir, } if (value) { + skp = smk_find_entry(csp); rcu_read_lock(); - may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list); + may = smk_access_entry(csp, dsp, &skp->smk_rules); rcu_read_unlock(); /* @@ -841,7 +880,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, return; } -/* +/** * smack_inode_getxattr - Smack check on getxattr * @dentry: the object * @name: unused @@ -858,7 +897,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name) return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad); } -/* +/** * smack_inode_removexattr - Smack check on removexattr * @dentry: the object * @name: name of the attribute @@ -1088,36 +1127,31 @@ static int smack_file_lock(struct file *file, unsigned int cmd) * @cmd: what action to check * @arg: unused * + * Generally these operations are harmless. + * File locking operations present an obvious mechanism + * for passing information, so they require write access. + * * Returns 0 if current has access, error code otherwise */ static int smack_file_fcntl(struct file *file, unsigned int cmd, unsigned long arg) { struct smk_audit_info ad; - int rc; + int rc = 0; - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); - smk_ad_setfield_u_fs_path(&ad, file->f_path); switch (cmd) { - case F_DUPFD: - case F_GETFD: - case F_GETFL: case F_GETLK: - case F_GETOWN: - case F_GETSIG: - rc = smk_curacc(file->f_security, MAY_READ, &ad); - break; - case F_SETFD: - case F_SETFL: case F_SETLK: case F_SETLKW: case F_SETOWN: case F_SETSIG: + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); + smk_ad_setfield_u_fs_path(&ad, file->f_path); rc = smk_curacc(file->f_security, MAY_WRITE, &ad); break; default: - rc = smk_curacc(file->f_security, MAY_READWRITE, &ad); + break; } return rc; @@ -1138,6 +1172,7 @@ static int smack_file_mmap(struct file *file, unsigned long flags, unsigned long addr, unsigned long addr_only) { + struct smack_known *skp; struct smack_rule *srp; struct task_smack *tsp; char *sp; @@ -1170,6 +1205,7 @@ static int smack_file_mmap(struct file *file, tsp = current_security(); sp = smk_of_current(); + skp = smk_find_entry(sp); rc = 0; rcu_read_lock(); @@ -1177,15 +1213,8 @@ static int smack_file_mmap(struct file *file, * For each Smack rule associated with the subject * label verify that the SMACK64MMAP also has access * to that rule's object label. - * - * Because neither of the labels comes - * from the networking code it is sufficient - * to compare pointers. */ - list_for_each_entry_rcu(srp, &smack_rule_list, list) { - if (srp->smk_subject != sp) - continue; - + list_for_each_entry_rcu(srp, &skp->smk_rules, list) { osmack = srp->smk_object; /* * Matching labels always allows access. @@ -1214,7 +1243,8 @@ static int smack_file_mmap(struct file *file, * If there isn't one a SMACK64MMAP subject * can't have as much access as current. */ - mmay = smk_access_entry(msmack, osmack, &smack_rule_list); + skp = smk_find_entry(msmack); + mmay = smk_access_entry(msmack, osmack, &skp->smk_rules); if (mmay == -ENOENT) { rc = -EACCES; break; @@ -1315,6 +1345,24 @@ static int smack_file_receive(struct file *file) return smk_curacc(file->f_security, may, &ad); } +/** + * smack_dentry_open - Smack dentry open processing + * @file: the object + * @cred: unused + * + * Set the security blob in the file structure. + * + * Returns 0 + */ +static int smack_dentry_open(struct file *file, const struct cred *cred) +{ + struct inode_smack *isp = file->f_path.dentry->d_inode->i_security; + + file->f_security = isp->smk_inode; + + return 0; +} + /* * Task hooks */ @@ -1455,15 +1503,17 @@ static int smack_kernel_create_files_as(struct cred *new, /** * smk_curacc_on_task - helper to log task related access * @p: the task object - * @access : the access requested + * @access: the access requested + * @caller: name of the calling function for audit * * Return 0 if access is permitted */ -static int smk_curacc_on_task(struct task_struct *p, int access) +static int smk_curacc_on_task(struct task_struct *p, int access, + const char *caller) { struct smk_audit_info ad; - smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); smk_ad_setfield_u_tsk(&ad, p); return smk_curacc(smk_of_task(task_security(p)), access, &ad); } @@ -1477,7 +1527,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access) */ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) { - return smk_curacc_on_task(p, MAY_WRITE); + return smk_curacc_on_task(p, MAY_WRITE, __func__); } /** @@ -1488,7 +1538,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid) */ static int smack_task_getpgid(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1499,7 +1549,7 @@ static int smack_task_getpgid(struct task_struct *p) */ static int smack_task_getsid(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1527,7 +1577,7 @@ static int smack_task_setnice(struct task_struct *p, int nice) rc = cap_task_setnice(p, nice); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1544,7 +1594,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) rc = cap_task_setioprio(p, ioprio); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1556,7 +1606,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio) */ static int smack_task_getioprio(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1573,7 +1623,7 @@ static int smack_task_setscheduler(struct task_struct *p) rc = cap_task_setscheduler(p); if (rc == 0) - rc = smk_curacc_on_task(p, MAY_WRITE); + rc = smk_curacc_on_task(p, MAY_WRITE, __func__); return rc; } @@ -1585,7 +1635,7 @@ static int smack_task_setscheduler(struct task_struct *p) */ static int smack_task_getscheduler(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_READ); + return smk_curacc_on_task(p, MAY_READ, __func__); } /** @@ -1596,7 +1646,7 @@ static int smack_task_getscheduler(struct task_struct *p) */ static int smack_task_movememory(struct task_struct *p) { - return smk_curacc_on_task(p, MAY_WRITE); + return smk_curacc_on_task(p, MAY_WRITE, __func__); } /** @@ -1711,7 +1761,7 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) ssp->smk_in = csp; ssp->smk_out = csp; - ssp->smk_packet[0] = '\0'; + ssp->smk_packet = NULL; sk->sk_security = ssp; @@ -2753,6 +2803,7 @@ static int smack_unix_stream_connect(struct sock *sock, { struct socket_smack *ssp = sock->sk_security; struct socket_smack *osp = other->sk_security; + struct socket_smack *nsp = newsk->sk_security; struct smk_audit_info ad; int rc = 0; @@ -2762,6 +2813,14 @@ static int smack_unix_stream_connect(struct sock *sock, if (!capable(CAP_MAC_OVERRIDE)) rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); + /* + * Cross reference the peer labels for SO_PEERSEC. + */ + if (rc == 0) { + nsp->smk_packet = ssp->smk_out; + ssp->smk_packet = osp->smk_out; + } + return rc; } @@ -2813,16 +2872,17 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, return smack_netlabel_send(sock->sk, sip); } - /** * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack * @sap: netlabel secattr - * @sip: where to put the result + * @ssp: socket security information * - * Copies a smack label into sip + * Returns a pointer to a Smack label found on the label list. */ -static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) +static char *smack_from_secattr(struct netlbl_lsm_secattr *sap, + struct socket_smack *ssp) { + struct smack_known *skp; char smack[SMK_LABELLEN]; char *sp; int pcat; @@ -2852,15 +2912,43 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) * we are already done. WeeHee. */ if (sap->attr.mls.lvl == smack_cipso_direct) { - memcpy(sip, smack, SMK_MAXLEN); - return; + /* + * The label sent is usually on the label list. + * + * If it is not we may still want to allow the + * delivery. + * + * If the recipient is accepting all packets + * because it is using the star ("*") label + * for SMACK64IPIN provide the web ("@") label + * so that a directed response will succeed. + * This is not very correct from a MAC point + * of view, but gets around the problem that + * locking prevents adding the newly discovered + * label to the list. + * The case where the recipient is not using + * the star label should obviously fail. + * The easy way to do this is to provide the + * star label as the subject label. + */ + skp = smk_find_entry(smack); + if (skp != NULL) + return skp->smk_known; + if (ssp != NULL && + ssp->smk_in == smack_known_star.smk_known) + return smack_known_web.smk_known; + return smack_known_star.smk_known; } /* * Look it up in the supplied table if it is not * a direct mapping. */ - smack_from_cipso(sap->attr.mls.lvl, smack, sip); - return; + sp = smack_from_cipso(sap->attr.mls.lvl, smack); + if (sp != NULL) + return sp; + if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known) + return smack_known_web.smk_known; + return smack_known_star.smk_known; } if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { /* @@ -2875,16 +2963,14 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) * secid is from a fallback. */ BUG_ON(sp == NULL); - strncpy(sip, sp, SMK_MAXLEN); - return; + return sp; } /* * Without guidance regarding the smack value * for the packet fall back on the network * ambient value. */ - strncpy(sip, smack_net_ambient, SMK_MAXLEN); - return; + return smack_net_ambient; } /** @@ -2898,7 +2984,6 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) { struct netlbl_lsm_secattr secattr; struct socket_smack *ssp = sk->sk_security; - char smack[SMK_LABELLEN]; char *csp; int rc; struct smk_audit_info ad; @@ -2911,10 +2996,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); - if (rc == 0) { - smack_from_secattr(&secattr, smack); - csp = smack; - } else + if (rc == 0) + csp = smack_from_secattr(&secattr, ssp); + else csp = smack_net_ambient; netlbl_secattr_destroy(&secattr); @@ -2951,15 +3035,19 @@ static int smack_socket_getpeersec_stream(struct socket *sock, int __user *optlen, unsigned len) { struct socket_smack *ssp; - int slen; + char *rcp = ""; + int slen = 1; int rc = 0; ssp = sock->sk->sk_security; - slen = strlen(ssp->smk_packet) + 1; + if (ssp->smk_packet != NULL) { + rcp = ssp->smk_packet; + slen = strlen(rcp) + 1; + } if (slen > len) rc = -ERANGE; - else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) + else if (copy_to_user(optval, rcp, slen) != 0) rc = -EFAULT; if (put_user(slen, optlen) != 0) @@ -2982,8 +3070,8 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, { struct netlbl_lsm_secattr secattr; - struct socket_smack *sp; - char smack[SMK_LABELLEN]; + struct socket_smack *ssp = NULL; + char *sp; int family = PF_UNSPEC; u32 s = 0; /* 0 is the invalid secid */ int rc; @@ -2998,17 +3086,19 @@ static int smack_socket_getpeersec_dgram(struct socket *sock, family = sock->sk->sk_family; if (family == PF_UNIX) { - sp = sock->sk->sk_security; - s = smack_to_secid(sp->smk_out); + ssp = sock->sk->sk_security; + s = smack_to_secid(ssp->smk_out); } else if (family == PF_INET || family == PF_INET6) { /* * Translate what netlabel gave us. */ + if (sock != NULL && sock->sk != NULL) + ssp = sock->sk->sk_security; netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) { - smack_from_secattr(&secattr, smack); - s = smack_to_secid(smack); + sp = smack_from_secattr(&secattr, ssp); + s = smack_to_secid(sp); } netlbl_secattr_destroy(&secattr); } @@ -3056,7 +3146,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct netlbl_lsm_secattr secattr; struct sockaddr_in addr; struct iphdr *hdr; - char smack[SMK_LABELLEN]; + char *sp; int rc; struct smk_audit_info ad; @@ -3067,9 +3157,9 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, family, &secattr); if (rc == 0) - smack_from_secattr(&secattr, smack); + sp = smack_from_secattr(&secattr, ssp); else - strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); + sp = smack_known_huh.smk_known; netlbl_secattr_destroy(&secattr); #ifdef CONFIG_AUDIT @@ -3082,7 +3172,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, * Receiving a packet requires that the other end be able to write * here. Read access is not required. */ - rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad); + rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad); if (rc != 0) return rc; @@ -3090,7 +3180,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, * Save the peer's label in the request_sock so we can later setup * smk_packet in the child socket so that SO_PEERCRED can report it. */ - req->peer_secid = smack_to_secid(smack); + req->peer_secid = smack_to_secid(sp); /* * We need to decide if we want to label the incoming connection here @@ -3103,7 +3193,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, if (smack_host_label(&addr) == NULL) { rcu_read_unlock(); netlbl_secattr_init(&secattr); - smack_to_secattr(smack, &secattr); + smack_to_secattr(sp, &secattr); rc = netlbl_req_setattr(req, &secattr); netlbl_secattr_destroy(&secattr); } else { @@ -3125,13 +3215,11 @@ static void smack_inet_csk_clone(struct sock *sk, const struct request_sock *req) { struct socket_smack *ssp = sk->sk_security; - char *smack; - if (req->peer_secid != 0) { - smack = smack_from_secid(req->peer_secid); - strncpy(ssp->smk_packet, smack, SMK_MAXLEN); - } else - ssp->smk_packet[0] = '\0'; + if (req->peer_secid != 0) + ssp->smk_packet = smack_from_secid(req->peer_secid); + else + ssp->smk_packet = NULL; } /* @@ -3409,6 +3497,8 @@ struct security_operations smack_ops = { .sb_umount = smack_sb_umount, .bprm_set_creds = smack_bprm_set_creds, + .bprm_committing_creds = smack_bprm_committing_creds, + .bprm_secureexec = smack_bprm_secureexec, .inode_alloc_security = smack_inode_alloc_security, .inode_free_security = smack_inode_free_security, @@ -3440,6 +3530,8 @@ struct security_operations smack_ops = { .file_send_sigiotask = smack_file_send_sigiotask, .file_receive = smack_file_receive, + .dentry_open = smack_dentry_open, + .cred_alloc_blank = smack_cred_alloc_blank, .cred_free = smack_cred_free, .cred_prepare = smack_cred_prepare, |