diff options
Diffstat (limited to 'security/smack/smackfs.c')
| -rw-r--r-- | security/smack/smackfs.c | 138 |
1 files changed, 78 insertions, 60 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 15aa37f65b39..6ba283783b70 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -24,6 +24,7 @@ #include <net/cipso_ipv4.h> #include <linux/seq_file.h> #include <linux/ctype.h> +#include <linux/audit.h> #include "smack.h" /* @@ -45,6 +46,7 @@ enum smk_inos { */ static DEFINE_MUTEX(smack_list_lock); static DEFINE_MUTEX(smack_cipso_lock); +static DEFINE_MUTEX(smack_ambient_lock); /* * This is the "ambient" label for network traffic. @@ -72,17 +74,25 @@ struct smk_list_entry *smack_list; #define SEQ_READ_FINISHED 1 /* - * Disable concurrent writing open() operations - */ -static struct semaphore smack_write_sem; - -/* * Values for parsing cipso rules * SMK_DIGITLEN: Length of a digit field in a rule. - * SMK_CIPSOMEN: Minimum possible cipso rule length. + * SMK_CIPSOMIN: Minimum possible cipso rule length. + * SMK_CIPSOMAX: Maximum possible cipso rule length. */ #define SMK_DIGITLEN 4 -#define SMK_CIPSOMIN (SMK_MAXLEN + 2 * SMK_DIGITLEN) +#define SMK_CIPSOMIN (SMK_LABELLEN + 2 * SMK_DIGITLEN) +#define SMK_CIPSOMAX (SMK_CIPSOMIN + SMACK_CIPSO_MAXCATNUM * SMK_DIGITLEN) + +/* + * Values for parsing MAC rules + * SMK_ACCESS: Maximum possible combination of access permissions + * SMK_ACCESSLEN: Maximum length for a rule access field + * SMK_LOADLEN: Smack rule length + */ +#define SMK_ACCESS "rwxa" +#define SMK_ACCESSLEN (sizeof(SMK_ACCESS) - 1) +#define SMK_LOADLEN (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSLEN) + /* * Seq_file read operations for /smack/load @@ -153,32 +163,7 @@ static struct seq_operations load_seq_ops = { */ static int smk_open_load(struct inode *inode, struct file *file) { - if ((file->f_flags & O_ACCMODE) == O_RDONLY) - return seq_open(file, &load_seq_ops); - - if (down_interruptible(&smack_write_sem)) - return -ERESTARTSYS; - - return 0; -} - -/** - * smk_release_load - release() for /smack/load - * @inode: inode structure representing file - * @file: "load" file pointer - * - * For a reading session, use the seq_file release - * implementation. - * Otherwise, we are at the end of a writing session so - * clean everything up. - */ -static int smk_release_load(struct inode *inode, struct file *file) -{ - if ((file->f_flags & O_ACCMODE) == O_RDONLY) - return seq_release(inode, file); - - up(&smack_write_sem); - return 0; + return seq_open(file, &load_seq_ops); } /** @@ -227,14 +212,10 @@ static void smk_set_access(struct smack_rule *srp) * The format is exactly: * char subject[SMK_LABELLEN] * char object[SMK_LABELLEN] - * char access[SMK_ACCESSKINDS] - * - * Anything following is commentary and ignored. + * char access[SMK_ACCESSLEN] * - * writes must be SMK_LABELLEN+SMK_LABELLEN+4 bytes. + * writes must be SMK_LABELLEN+SMK_LABELLEN+SMK_ACCESSLEN bytes. */ -#define MINIMUM_LOAD (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSKINDS) - static ssize_t smk_write_load(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -251,7 +232,7 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf, return -EPERM; if (*ppos != 0) return -EINVAL; - if (count < MINIMUM_LOAD) + if (count != SMK_LOADLEN) return -EINVAL; data = kzalloc(count, GFP_KERNEL); @@ -330,7 +311,7 @@ static const struct file_operations smk_load_ops = { .read = seq_read, .llseek = seq_lseek, .write = smk_write_load, - .release = smk_release_load, + .release = seq_release, }; /** @@ -342,6 +323,9 @@ void smk_cipso_doi(void) struct cipso_v4_doi *doip; struct netlbl_audit audit_info; + audit_info.loginuid = audit_get_loginuid(current); + audit_info.secid = smack_to_secid(current->security); + rc = netlbl_cfg_map_del(NULL, &audit_info); if (rc != 0) printk(KERN_WARNING "%s:%d remove rc = %d\n", @@ -363,6 +347,30 @@ void smk_cipso_doi(void) __func__, __LINE__, rc); } +/** + * smk_unlbl_ambient - initialize the unlabeled domain + */ +void smk_unlbl_ambient(char *oldambient) +{ + int rc; + struct netlbl_audit audit_info; + + audit_info.loginuid = audit_get_loginuid(current); + audit_info.secid = smack_to_secid(current->security); + + if (oldambient != NULL) { + rc = netlbl_cfg_map_del(oldambient, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + } + + rc = netlbl_cfg_unlbl_add_map(smack_net_ambient, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d add rc = %d\n", + __func__, __LINE__, rc); +} + /* * Seq_file read operations for /smack/cipso */ @@ -484,7 +492,7 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf, return -EPERM; if (*ppos != 0) return -EINVAL; - if (count <= SMK_CIPSOMIN) + if (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX) return -EINVAL; data = kzalloc(count + 1, GFP_KERNEL); @@ -518,7 +526,7 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf, if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM) goto out; - if (count <= (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) + if (count != (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) goto out; memset(mapcatset, 0, sizeof(mapcatset)); @@ -709,7 +717,6 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf, size_t cn, loff_t *ppos) { ssize_t rc; - char out[SMK_LABELLEN]; int asize; if (*ppos != 0) @@ -717,23 +724,18 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf, /* * Being careful to avoid a problem in the case where * smack_net_ambient gets changed in midstream. - * Since smack_net_ambient is always set with a value - * from the label list, including initially, and those - * never get freed, the worst case is that the pointer - * gets changed just after this strncpy, in which case - * the value passed up is incorrect. Locking around - * smack_net_ambient wouldn't be any better than this - * copy scheme as by the time the caller got to look - * at the ambient value it would have cleared the lock - * and been changed. */ - strncpy(out, smack_net_ambient, SMK_LABELLEN); - asize = strlen(out) + 1; + mutex_lock(&smack_ambient_lock); - if (cn < asize) - return -EINVAL; + asize = strlen(smack_net_ambient) + 1; + + if (cn >= asize) + rc = simple_read_from_buffer(buf, cn, ppos, + smack_net_ambient, asize); + else + rc = -EINVAL; - rc = simple_read_from_buffer(buf, cn, ppos, out, asize); + mutex_unlock(&smack_ambient_lock); return rc; } @@ -751,6 +753,7 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { char in[SMK_LABELLEN]; + char *oldambient; char *smack; if (!capable(CAP_MAC_ADMIN)) @@ -766,7 +769,13 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf, if (smack == NULL) return -EINVAL; + mutex_lock(&smack_ambient_lock); + + oldambient = smack_net_ambient; smack_net_ambient = smack; + smk_unlbl_ambient(oldambient); + + mutex_unlock(&smack_ambient_lock); return count; } @@ -956,12 +965,21 @@ static struct vfsmount *smackfs_mount; * * register the smackfs * - * Returns 0 unless the registration fails. + * Do not register smackfs if Smack wasn't enabled + * on boot. We can not put this method normally under the + * smack_init() code path since the security subsystem get + * initialized before the vfs caches. + * + * Returns true if we were not chosen on boot or if + * we were chosen and filesystem registration succeeded. */ static int __init init_smk_fs(void) { int err; + if (!security_module_enable(&smack_ops)) + return 0; + err = register_filesystem(&smk_fs_type); if (!err) { smackfs_mount = kern_mount(&smk_fs_type); @@ -972,8 +990,8 @@ static int __init init_smk_fs(void) } } - sema_init(&smack_write_sem, 1); smk_cipso_doi(); + smk_unlbl_ambient(NULL); return err; } |