diff options
Diffstat (limited to 'security/selinux/hooks.c')
-rw-r--r-- | security/selinux/hooks.c | 201 |
1 files changed, 124 insertions, 77 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 564079c5c49d..9e591e5989be 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -126,6 +126,7 @@ int selinux_enabled = 1; #endif static struct kmem_cache *sel_inode_cache; +static struct kmem_cache *file_security_cache; /** * selinux_secmark_enabled - Check to see if SECMARK is currently enabled @@ -254,10 +255,21 @@ static void inode_free_security(struct inode *inode) struct inode_security_struct *isec = inode->i_security; struct superblock_security_struct *sbsec = inode->i_sb->s_security; - spin_lock(&sbsec->isec_lock); - if (!list_empty(&isec->list)) + /* + * As not all inode security structures are in a list, we check for + * empty list outside of the lock to make sure that we won't waste + * time taking a lock doing nothing. + * + * The list_del_init() function can be safely called more than once. + * It should not be possible for this function to be called with + * concurrent list_add(), but for better safety against future changes + * in the code, we use list_empty_careful() here. + */ + if (!list_empty_careful(&isec->list)) { + spin_lock(&sbsec->isec_lock); list_del_init(&isec->list); - spin_unlock(&sbsec->isec_lock); + spin_unlock(&sbsec->isec_lock); + } /* * The inode may still be referenced in a path walk and @@ -276,7 +288,7 @@ static int file_alloc_security(struct file *file) struct file_security_struct *fsec; u32 sid = current_sid(); - fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); + fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL); if (!fsec) return -ENOMEM; @@ -291,7 +303,7 @@ static void file_free_security(struct file *file) { struct file_security_struct *fsec = file->f_security; file->f_security = NULL; - kfree(fsec); + kmem_cache_free(file_security_cache, fsec); } static int superblock_alloc_security(struct super_block *sb) @@ -663,10 +675,9 @@ static int selinux_set_mnt_opts(struct super_block *sb, if (flags[i] == SBLABEL_MNT) continue; - rc = security_context_to_sid(mount_options[i], - strlen(mount_options[i]), &sid, GFP_KERNEL); + rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); if (rc) { - printk(KERN_WARNING "SELinux: security_context_to_sid" + printk(KERN_WARNING "SELinux: security_context_str_to_sid" "(%s) failed for (dev %s, type %s) errno=%d\n", mount_options[i], sb->s_id, name, rc); goto out; @@ -1100,7 +1111,7 @@ static void selinux_write_opts(struct seq_file *m, seq_puts(m, prefix); if (has_comma) seq_putc(m, '\"'); - seq_puts(m, opts->mnt_opts[i]); + seq_escape(m, opts->mnt_opts[i], "\"\n\\"); if (has_comma) seq_putc(m, '\"'); } @@ -1698,6 +1709,32 @@ out: return rc; } +/* + * Determine the label for an inode that might be unioned. + */ +static int selinux_determine_inode_label(const struct inode *dir, + const struct qstr *name, + u16 tclass, + u32 *_new_isid) +{ + const struct superblock_security_struct *sbsec = dir->i_sb->s_security; + const struct inode_security_struct *dsec = dir->i_security; + const struct task_security_struct *tsec = current_security(); + + if ((sbsec->flags & SE_SBINITIALIZED) && + (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { + *_new_isid = sbsec->mntpoint_sid; + } else if ((sbsec->flags & SBLABEL_MNT) && + tsec->create_sid) { + *_new_isid = tsec->create_sid; + } else { + return security_transition_sid(tsec->sid, dsec->sid, tclass, + name, _new_isid); + } + + return 0; +} + /* Check whether a task can create a file. */ static int may_create(struct inode *dir, struct dentry *dentry, @@ -1714,7 +1751,6 @@ static int may_create(struct inode *dir, sbsec = dir->i_sb->s_security; sid = tsec->sid; - newsid = tsec->create_sid; ad.type = LSM_AUDIT_DATA_DENTRY; ad.u.dentry = dentry; @@ -1725,12 +1761,10 @@ static int may_create(struct inode *dir, if (rc) return rc; - if (!newsid || !(sbsec->flags & SBLABEL_MNT)) { - rc = security_transition_sid(sid, dsec->sid, tclass, - &dentry->d_name, &newsid); - if (rc) - return rc; - } + rc = selinux_determine_inode_label(dir, &dentry->d_name, tclass, + &newsid); + if (rc) + return rc; rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); if (rc) @@ -2583,15 +2617,12 @@ static int selinux_sb_remount(struct super_block *sb, void *data) for (i = 0; i < opts.num_mnt_opts; i++) { u32 sid; - size_t len; if (flags[i] == SBLABEL_MNT) continue; - len = strlen(mount_options[i]); - rc = security_context_to_sid(mount_options[i], len, &sid, - GFP_KERNEL); + rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); if (rc) { - printk(KERN_WARNING "SELinux: security_context_to_sid" + printk(KERN_WARNING "SELinux: security_context_str_to_sid" "(%s) failed for (dev %s, type %s) errno=%d\n", mount_options[i], sb->s_id, sb->s_type->name, rc); goto out_free_opts; @@ -2704,32 +2735,14 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode, struct qstr *name, void **ctx, u32 *ctxlen) { - const struct cred *cred = current_cred(); - struct task_security_struct *tsec; - struct inode_security_struct *dsec; - struct superblock_security_struct *sbsec; - struct inode *dir = d_backing_inode(dentry->d_parent); u32 newsid; int rc; - tsec = cred->security; - dsec = dir->i_security; - sbsec = dir->i_sb->s_security; - - if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { - newsid = tsec->create_sid; - } else { - rc = security_transition_sid(tsec->sid, dsec->sid, - inode_mode_to_security_class(mode), - name, - &newsid); - if (rc) { - printk(KERN_WARNING - "%s: security_transition_sid failed, rc=%d\n", - __func__, -rc); - return rc; - } - } + rc = selinux_determine_inode_label(d_inode(dentry->d_parent), name, + inode_mode_to_security_class(mode), + &newsid); + if (rc) + return rc; return security_sid_to_context(newsid, (char **)ctx, ctxlen); } @@ -2752,22 +2765,12 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, sid = tsec->sid; newsid = tsec->create_sid; - if ((sbsec->flags & SE_SBINITIALIZED) && - (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) - newsid = sbsec->mntpoint_sid; - else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) { - rc = security_transition_sid(sid, dsec->sid, - inode_mode_to_security_class(inode->i_mode), - qstr, &newsid); - if (rc) { - printk(KERN_WARNING "%s: " - "security_transition_sid failed, rc=%d (dev=%s " - "ino=%ld)\n", - __func__, - -rc, inode->i_sb->s_id, inode->i_ino); - return rc; - } - } + rc = selinux_determine_inode_label( + dir, qstr, + inode_mode_to_security_class(inode->i_mode), + &newsid); + if (rc) + return rc; /* Possibly defer initialization to selinux_complete_init. */ if (sbsec->flags & SE_SBINITIALIZED) { @@ -2940,7 +2943,8 @@ static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) return dentry_has_perm(cred, dentry, FILE__SETATTR); - if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)) + if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE) + && !(ia_valid & ATTR_FILE)) av |= FILE__OPEN; return dentry_has_perm(cred, dentry, av); @@ -3160,7 +3164,7 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, if (!value || !size) return -EACCES; - rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL); + rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); if (rc) return rc; @@ -3228,6 +3232,46 @@ static void selinux_file_free_security(struct file *file) file_free_security(file); } +/* + * Check whether a task has the ioctl permission and cmd + * operation to an inode. + */ +static int ioctl_has_perm(const struct cred *cred, struct file *file, + u32 requested, u16 cmd) +{ + struct common_audit_data ad; + struct file_security_struct *fsec = file->f_security; + struct inode *inode = file_inode(file); + struct inode_security_struct *isec = inode->i_security; + struct lsm_ioctlop_audit ioctl; + u32 ssid = cred_sid(cred); + int rc; + u8 driver = cmd >> 8; + u8 xperm = cmd & 0xff; + + ad.type = LSM_AUDIT_DATA_IOCTL_OP; + ad.u.op = &ioctl; + ad.u.op->cmd = cmd; + ad.u.op->path = file->f_path; + + if (ssid != fsec->sid) { + rc = avc_has_perm(ssid, fsec->sid, + SECCLASS_FD, + FD__USE, + &ad); + if (rc) + goto out; + } + + if (unlikely(IS_PRIVATE(inode))) + return 0; + + rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, + requested, driver, xperm, &ad); +out: + return rc; +} + static int selinux_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3270,7 +3314,7 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd, * to the file's ioctl() function. */ default: - error = file_has_perm(cred, file, FILE__IOCTL); + error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); } return error; } @@ -4520,6 +4564,7 @@ static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority sksec->peer_sid = SECINITSID_UNLABELED; sksec->sid = SECINITSID_UNLABELED; + sksec->sclass = SECCLASS_SOCKET; selinux_netlbl_sk_security_reset(sksec); sk->sk_security = sksec; @@ -4819,7 +4864,7 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, return NF_ACCEPT; } -static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops, +static unsigned int selinux_ipv4_forward(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { @@ -4827,7 +4872,7 @@ static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops, } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) -static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops, +static unsigned int selinux_ipv6_forward(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { @@ -4851,7 +4896,7 @@ static unsigned int selinux_ip_output(struct sk_buff *skb, if (sk) { struct sk_security_struct *sksec; - if (sk->sk_state == TCP_LISTEN) + if (sk_listener(sk)) /* if the socket is the listening state then this * packet is a SYN-ACK packet which means it needs to * be labeled based on the connection/request_sock and @@ -4877,7 +4922,7 @@ static unsigned int selinux_ip_output(struct sk_buff *skb, return NF_ACCEPT; } -static unsigned int selinux_ipv4_output(const struct nf_hook_ops *ops, +static unsigned int selinux_ipv4_output(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { @@ -4958,7 +5003,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, * unfortunately, this means more work, but it is only once per * connection. */ if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && - !(sk != NULL && sk->sk_state == TCP_LISTEN)) + !(sk && sk_listener(sk))) return NF_ACCEPT; #endif @@ -4975,7 +5020,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, secmark_perm = PACKET__SEND; peer_sid = SECINITSID_KERNEL; } - } else if (sk->sk_state == TCP_LISTEN) { + } else if (sk_listener(sk)) { /* Locally generated packet but the associated socket is in the * listening state which means this is a SYN-ACK packet. In * this particular case the correct security label is assigned @@ -4986,7 +5031,11 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, * selinux_inet_conn_request(). See also selinux_ip_output() * for similar problems. */ u32 skb_sid; - struct sk_security_struct *sksec = sk->sk_security; + struct sk_security_struct *sksec; + + if (sk->sk_state == TCP_NEW_SYN_RECV) + sk = inet_reqsk(sk)->rsk_listener; + sksec = sk->sk_security; if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) return NF_DROP; /* At this point, if the returned skb peerlbl is SECSID_NULL @@ -5052,7 +5101,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, return NF_ACCEPT; } -static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops, +static unsigned int selinux_ipv4_postroute(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { @@ -5060,7 +5109,7 @@ static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops, } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) -static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops, +static unsigned int selinux_ipv6_postroute(void *priv, struct sk_buff *skb, const struct nf_hook_state *state) { @@ -6042,6 +6091,9 @@ static __init int selinux_init(void) sel_inode_cache = kmem_cache_create("selinux_inode_security", sizeof(struct inode_security_struct), 0, SLAB_PANIC, NULL); + file_security_cache = kmem_cache_create("selinux_file_security", + sizeof(struct file_security_struct), + 0, SLAB_PANIC, NULL); avc_init(); security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks)); @@ -6080,21 +6132,18 @@ security_initcall(selinux_init); static struct nf_hook_ops selinux_nf_ops[] = { { .hook = selinux_ipv4_postroute, - .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_POST_ROUTING, .priority = NF_IP_PRI_SELINUX_LAST, }, { .hook = selinux_ipv4_forward, - .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_FORWARD, .priority = NF_IP_PRI_SELINUX_FIRST, }, { .hook = selinux_ipv4_output, - .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_LOCAL_OUT, .priority = NF_IP_PRI_SELINUX_FIRST, @@ -6102,14 +6151,12 @@ static struct nf_hook_ops selinux_nf_ops[] = { #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) { .hook = selinux_ipv6_postroute, - .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_POST_ROUTING, .priority = NF_IP6_PRI_SELINUX_LAST, }, { .hook = selinux_ipv6_forward, - .owner = THIS_MODULE, .pf = NFPROTO_IPV6, .hooknum = NF_INET_FORWARD, .priority = NF_IP6_PRI_SELINUX_FIRST, |