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Commit 066752a3 authored by Stephen D. Smalley's avatar Stephen D. Smalley Committed by Linus Torvalds
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[PATCH] SELinux: eliminate unaligned accesses by policy loading code 

This patch rewrites the SELinux next_entry() function and all callers to
copy entry data from the binary policy into properly aligned buffers,
eliminating unaligned accesses.  This patch is in response to a bug report
from Prarit Bhargava for SELinux and ia64, and he has confirmed that this
patch eliminates the unaligned access warnings.
Signed-off-by: default avatarStephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: default avatarJames Morris <jmorris@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 263891c2
Expand all Show whitespace changes
Inline Side-by-side
Showing with 201 additions and 250 deletions
security/selinux/ss/avtab.c
View file @ 066752a3
......@@ -303,20 +303,25 @@ void avtab_hash_eval(struct avtab *h, char *tag)
int avtab_read_item(void *fp, struct avtab_datum *avdatum, struct avtab_key *avkey)
{
__u32 *buf;
__u32 items, items2;
u32 buf[7];
u32 items, items2;
int rc;
memset(avkey, 0, sizeof(struct avtab_key));
memset(avdatum, 0, sizeof(struct avtab_datum));
buf = next_entry(fp, sizeof(__u32));
if (!buf) {
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0) {
printk(KERN_ERR "security: avtab: truncated entry\n");
goto bad;
}
items2 = le32_to_cpu(buf[0]);
buf = next_entry(fp, sizeof(__u32)*items2);
if (!buf) {
if (items2 > ARRAY_SIZE(buf)) {
printk(KERN_ERR "security: avtab: entry overflow\n");
goto bad;
}
rc = next_entry(buf, fp, sizeof(u32)*items2);
if (rc < 0) {
printk(KERN_ERR "security: avtab: truncated entry\n");
goto bad;
}
......@@ -362,21 +367,22 @@ int avtab_read_item(void *fp, struct avtab_datum *avdatum, struct avtab_key *avk
int avtab_read(struct avtab *a, void *fp, u32 config)
{
int i, rc = -EINVAL;
int rc;
struct avtab_key avkey;
struct avtab_datum avdatum;
u32 *buf;
u32 nel;
u32 buf[1];
u32 nel, i;
buf = next_entry(fp, sizeof(u32));
if (!buf) {
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0) {
printk(KERN_ERR "security: avtab: truncated table\n");
goto bad;
}
nel = le32_to_cpu(buf[0]);
if (!nel) {
printk(KERN_ERR "security: avtab: table is empty\n");
rc = -EINVAL;
goto bad;
}
for (i = 0; i < nel; i++) {
......
security/selinux/ss/conditional.c
View file @ 066752a3
......@@ -219,15 +219,16 @@ int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
{
char *key = NULL;
struct cond_bool_datum *booldatum;
__u32 *buf, len;
u32 buf[3], len;
int rc;
booldatum = kmalloc(sizeof(struct cond_bool_datum), GFP_KERNEL);
if (!booldatum)
return -1;
memset(booldatum, 0, sizeof(struct cond_bool_datum));
buf = next_entry(fp, sizeof(__u32) * 3);
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto err;
booldatum->value = le32_to_cpu(buf[0]);
......@@ -238,13 +239,12 @@ int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
len = le32_to_cpu(buf[2]);
buf = next_entry(fp, len);
if (!buf)
goto err;
key = kmalloc(len + 1, GFP_KERNEL);
if (!key)
goto err;
memcpy(key, buf, len);
rc = next_entry(key, fp, len);
if (rc < 0)
goto err;
key[len] = 0;
if (hashtab_insert(h, key, booldatum))
goto err;
......@@ -262,15 +262,15 @@ static int cond_read_av_list(struct policydb *p, void *fp, struct cond_av_list *
struct avtab_key key;
struct avtab_datum datum;
struct avtab_node *node_ptr;
int len, i;
__u32 *buf;
__u8 found;
int rc;
u32 buf[1], i, len;
u8 found;
*ret_list = NULL;
len = 0;
buf = next_entry(fp, sizeof(__u32));
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
return -1;
len = le32_to_cpu(buf[0]);
......@@ -369,27 +369,27 @@ static int expr_isvalid(struct policydb *p, struct cond_expr *expr)
static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
{
__u32 *buf;
int len, i;
u32 buf[2], len, i;
int rc;
struct cond_expr *expr = NULL, *last = NULL;
buf = next_entry(fp, sizeof(__u32));
if (!buf)
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
return -1;
node->cur_state = le32_to_cpu(buf[0]);
len = 0;
buf = next_entry(fp, sizeof(__u32));
if (!buf)
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
return -1;
/* expr */
len = le32_to_cpu(buf[0]);
for (i = 0; i < len; i++ ) {
buf = next_entry(fp, sizeof(__u32) * 2);
if (!buf)
rc = next_entry(buf, fp, sizeof(u32) * 2);
if (rc < 0)
goto err;
expr = kmalloc(sizeof(struct cond_expr), GFP_KERNEL);
......@@ -425,11 +425,11 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp)
int cond_read_list(struct policydb *p, void *fp)
{
struct cond_node *node, *last = NULL;
__u32 *buf;
int i, len;
u32 buf[1], i, len;
int rc;
buf = next_entry(fp, sizeof(__u32));
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
return -1;
len = le32_to_cpu(buf[0]);
......
security/selinux/ss/ebitmap.c
View file @ 066752a3
......@@ -239,13 +239,13 @@ int ebitmap_read(struct ebitmap *e, void *fp)
{
int rc = -EINVAL;
struct ebitmap_node *n, *l;
u32 *buf, mapsize, count, i;
u32 buf[3], mapsize, count, i;
u64 map;
ebitmap_init(e);
buf = next_entry(fp, sizeof(u32)*3);
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto out;
mapsize = le32_to_cpu(buf[0]);
......@@ -269,8 +269,8 @@ int ebitmap_read(struct ebitmap *e, void *fp)
}
l = NULL;
for (i = 0; i < count; i++) {
buf = next_entry(fp, sizeof(u32));
if (!buf) {
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0) {
printk(KERN_ERR "security: ebitmap: truncated map\n");
goto bad;
}
......@@ -296,12 +296,11 @@ int ebitmap_read(struct ebitmap *e, void *fp)
n->startbit, (e->highbit - MAPSIZE));
goto bad_free;
}
buf = next_entry(fp, sizeof(u64));
if (!buf) {
rc = next_entry(&map, fp, sizeof(u64));
if (rc < 0) {
printk(KERN_ERR "security: ebitmap: truncated map\n");
goto bad_free;
}
memcpy(&map, buf, sizeof(u64));
n->map = le64_to_cpu(map);
if (!n->map) {
......
security/selinux/ss/mls.c
View file @ 066752a3
......@@ -402,10 +402,11 @@ void mls_user_destroy(struct user_datum *usrdatum)
int mls_read_perm(struct perm_datum *perdatum, void *fp)
{
u32 *buf;
u32 buf[1];
int rc;
buf = next_entry(fp, sizeof(u32));
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
return -EINVAL;
perdatum->base_perms = le32_to_cpu(buf[0]);
return 0;
......@@ -418,7 +419,8 @@ int mls_read_perm(struct perm_datum *perdatum, void *fp)
struct mls_level *mls_read_level(void *fp)
{
struct mls_level *l;
u32 *buf;
u32 buf[1];
int rc;
l = kmalloc(sizeof(*l), GFP_ATOMIC);
if (!l) {
......@@ -427,8 +429,8 @@ struct mls_level *mls_read_level(void *fp)
}
memset(l, 0, sizeof(*l));
buf = next_entry(fp, sizeof(u32));
if (!buf) {
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0) {
printk(KERN_ERR "security: mls: truncated level\n");
goto bad;
}
......@@ -453,16 +455,21 @@ struct mls_level *mls_read_level(void *fp)
*/
static int mls_read_range_helper(struct mls_range *r, void *fp)
{
u32 *buf;
int items, rc = -EINVAL;
u32 buf[2], items;
int rc;
buf = next_entry(fp, sizeof(u32));
if (!buf)
rc = next_entry(buf, fp, sizeof(u32));
if (rc < 0)
goto out;
items = le32_to_cpu(buf[0]);
buf = next_entry(fp, sizeof(u32) * items);
if (!buf) {
if (items > ARRAY_SIZE(buf)) {
printk(KERN_ERR "security: mls: range overflow\n");
rc = -EINVAL;
goto out;
}
rc = next_entry(buf, fp, sizeof(u32) * items);
if (rc < 0) {
printk(KERN_ERR "security: mls: truncated range\n");
goto out;
}
......@@ -515,10 +522,11 @@ int mls_read_range(struct context *c, void *fp)
int mls_read_class(struct class_datum *cladatum, void *fp)
{
struct mls_perms *p = &cladatum->mlsperms;
u32 *buf;
u32 buf[4];
int rc;
buf = next_entry(fp, sizeof(u32)*4);
if (!buf) {
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0) {
printk(KERN_ERR "security: mls: truncated mls permissions\n");
return -EINVAL;
}
......@@ -532,15 +540,13 @@ int mls_read_class(struct class_datum *cladatum, void *fp)
int mls_read_user(struct user_datum *usrdatum, void *fp)
{
struct mls_range_list *r, *l;
int rc = 0;
int rc;
u32 nel, i;
u32 *buf;
u32 buf[1];
buf = next_entry(fp, sizeof(u32));
if (!buf) {
rc = -EINVAL;
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto out;
}
nel = le32_to_cpu(buf[0]);
l = NULL;
for (i = 0; i < nel; i++) {
......@@ -569,10 +575,11 @@ int mls_read_user(struct user_datum *usrdatum, void *fp)
int mls_read_nlevels(struct policydb *p, void *fp)
{
u32 *buf;
u32 buf[1];
int rc;
buf = next_entry(fp, sizeof(u32));
if (!buf)
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
return -EINVAL;
p->nlevels = le32_to_cpu(buf[0]);
return 0;
......@@ -657,7 +664,7 @@ int sens_read(struct policydb *p, struct hashtab *h, void *fp)
char *key = NULL;
struct level_datum *levdatum;
int rc;
u32 *buf, len;
u32 buf[2], len;
levdatum = kmalloc(sizeof(*levdatum), GFP_ATOMIC);
if (!levdatum) {
......@@ -666,26 +673,21 @@ int sens_read(struct policydb *p, struct hashtab *h, void *fp)
}
memset(levdatum, 0, sizeof(*levdatum));
buf = next_entry(fp, sizeof(u32)*2);
if (!buf) {
rc = -EINVAL;
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto bad;
}
len = le32_to_cpu(buf[0]);
levdatum->isalias = le32_to_cpu(buf[1]);
buf = next_entry(fp, len);
if (!buf) {
rc = -EINVAL;
goto bad;
}
key = kmalloc(len + 1,GFP_ATOMIC);
if (!key) {
rc = -ENOMEM;
goto bad;
}
memcpy(key, buf, len);
rc = next_entry(key, fp, len);
if (rc < 0)
goto bad;
key[len] = 0;
levdatum->level = mls_read_level(fp);
......@@ -710,7 +712,7 @@ int cat_read(struct policydb *p, struct hashtab *h, void *fp)
char *key = NULL;
struct cat_datum *catdatum;
int rc;
u32 *buf, len;
u32 buf[3], len;
catdatum = kmalloc(sizeof(*catdatum), GFP_ATOMIC);
if (!catdatum) {
......@@ -719,27 +721,22 @@ int cat_read(struct policydb *p, struct hashtab *h, void *fp)
}
memset(catdatum, 0, sizeof(*catdatum));
buf = next_entry(fp, sizeof(u32)*3);
if (!buf) {
rc = -EINVAL;
rc = next_entry(buf, fp, sizeof buf);
if (rc < 0)
goto bad;
}
len = le32_to_cpu(buf[0]);
catdatum->value = le32_to_cpu(buf[1]);
catdatum->isalias = le32_to_cpu(buf[2]);
buf = next_entry(fp, len);
if (!buf) {
rc = -EINVAL;
goto bad;
}
key = kmalloc(len + 1,GFP_ATOMIC);
if (!key) {
rc = -ENOMEM;
goto bad;
}
memcpy(key, buf, len);
rc = next_entry(key, fp, len);
if (rc < 0)
goto bad;
key[len] = 0;
rc = hashtab_insert(h, key, catdatum);
......
security/selinux/ss/policydb.c
View file @ 066752a3
This diff is collapsed.
security/selinux/ss/policydb.h
View file @ 066752a3
......@@ -271,17 +271,15 @@ struct policy_file {
size_t len;
};
static inline void *next_entry(struct policy_file *fp, size_t bytes)
static inline int next_entry(void *buf, struct policy_file *fp, size_t bytes)
{
void *buf;
if (bytes > fp->len)
return NULL;
return -EINVAL;
buf = fp->data;
memcpy(buf, fp->data, bytes);
fp->data += bytes;
fp->len -= bytes;
return buf;
return 0;
}
#endif /* _SS_POLICYDB_H_ */
......
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