BACKPORT: netlabel: fix a problem when setting bits below the previously lowest bit

The NetLabel category (catmap) functions have a problem in that they
assume categories will be set in an increasing manner, e.g. the next
category set will always be larger than the last.  Unfortunately, this
is not a valid assumption and could result in problems when attempting
to set categories less than the startbit in the lowest catmap node.
In some cases kernel panics and other nasties can result.

This patch corrects the problem by checking for this and allocating a
new catmap node instance and placing it at the front of the list.

Cc: stable@vger.kernel.org
Reported-by: Christian Evans <frodox@zoho.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
(cherry-picked from upstream 41c3bd2039e0d7b3dc32313141773f20716ec524)

diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index f67440970d7e78d7177252eeafbaead56b74f6dd..c8ba2e29018ac096465090df97df4028de3ed41d 100644 (file)
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -395,10 +395,10 @@ int netlbl_secattr_catmap_walk(struct netlbl_lsm_secattr_catmap *catmap,
                               u32 offset);
 int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
                                   u32 offset);
-int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
+int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap **catmap,
                                 u32 bit,
                                 gfp_t flags);
-int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
+int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap **catmap,
                                 u32 start,
                                 u32 end,
                                 gfp_t flags);
@@ -506,14 +506,14 @@ static inline int netlbl_secattr_catmap_walk_rng(
        return -ENOENT;
 }
 static inline int netlbl_secattr_catmap_setbit(
-                                     struct netlbl_lsm_secattr_catmap *catmap,
+                                     struct netlbl_lsm_secattr_catmap **catmap,
                                      u32 bit,
                                      gfp_t flags)
 {
        return 0;
 }
 static inline int netlbl_secattr_catmap_setrng(
-                                     struct netlbl_lsm_secattr_catmap *catmap,
+                                     struct netlbl_lsm_secattr_catmap **catmap,
                                      u32 start,
                                      u32 end,
                                      gfp_t flags)

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index c48adc565e9239a45c600d791c8f97059e22696f..696b0ca48602f11ed2fb3b1a5bc4783f34607537 100644 (file)
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -974,7 +974,7 @@ static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
                                return -EPERM;
                        break;
                }
-               ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
+               ret_val = netlbl_secattr_catmap_setbit(&secattr->attr.mls.cat,
                                                       host_spot,
                                                       GFP_ATOMIC);
                if (ret_val != 0)
@@ -1076,7 +1076,7 @@ static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
        u32 iter;
 
        for (iter = 0; iter < net_cat_len; iter += 2) {
-               ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
+               ret_val = netlbl_secattr_catmap_setbit(&secattr->attr.mls.cat,
                                get_unaligned_be16(&net_cat[iter]),
                                GFP_ATOMIC);
                if (ret_val != 0)
@@ -1218,7 +1218,7 @@ static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
                else
                        cat_low = 0;
 
-               ret_val = netlbl_secattr_catmap_setrng(secattr->attr.mls.cat,
+               ret_val = netlbl_secattr_catmap_setrng(&secattr->attr.mls.cat,
                                                       cat_low,
                                                       cat_high,
                                                       GFP_ATOMIC);

diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index 7c94aedd0912777d6d0956f0f5b048f0f62ab97d..5b2a072fdd912cac352e0213d7fbe089c720748c 100644 (file)
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -523,7 +523,7 @@ int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
 
 /**
  * netlbl_secattr_catmap_setbit - Set a bit in a LSM secattr catmap
- * @catmap: the category bitmap
+ * @catmap: pointer to the category bitmap
  * @bit: the bit to set
  * @flags: memory allocation flags
  *
@@ -532,18 +532,25 @@ int netlbl_secattr_catmap_walk_rng(struct netlbl_lsm_secattr_catmap *catmap,
  * negative values on failure.
  *
  */
-int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
+int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap **catmap,
                                 u32 bit,
                                 gfp_t flags)
 {
-       struct netlbl_lsm_secattr_catmap *iter = catmap;
+       struct netlbl_lsm_secattr_catmap *iter = *catmap;
        u32 node_bit;
        u32 node_idx;
 
        while (iter->next != NULL &&
               bit >= (iter->startbit + NETLBL_CATMAP_SIZE))
                iter = iter->next;
-       if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
+       if (bit < iter->startbit) {
+               iter = netlbl_secattr_catmap_alloc(flags);
+               if (iter == NULL)
+                       return -ENOMEM;
+               iter->next = *catmap;
+               iter->startbit = bit & ~(NETLBL_CATMAP_SIZE - 1);
+               *catmap = iter;
+       } else if (bit >= (iter->startbit + NETLBL_CATMAP_SIZE)) {
                iter->next = netlbl_secattr_catmap_alloc(flags);
                if (iter->next == NULL)
                        return -ENOMEM;
@@ -561,7 +568,7 @@ int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
 
 /**
  * netlbl_secattr_catmap_setrng - Set a range of bits in a LSM secattr catmap
- * @catmap: the category bitmap
+ * @catmap: pointer to the category bitmap
  * @start: the starting bit
  * @end: the last bit in the string
  * @flags: memory allocation flags
@@ -571,15 +578,16 @@ int netlbl_secattr_catmap_setbit(struct netlbl_lsm_secattr_catmap *catmap,
  * on success, negative values on failure.
  *
  */
-int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
+int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap **catmap,
                                 u32 start,
                                 u32 end,
                                 gfp_t flags)
 {
        int ret_val = 0;
-       struct netlbl_lsm_secattr_catmap *iter = catmap;
+       struct netlbl_lsm_secattr_catmap *iter = *catmap;
        u32 iter_max_spot;
        u32 spot;
+       u32 orig_spot = iter->startbit;
 
        /* XXX - This could probably be made a bit faster by combining writes
         * to the catmap instead of setting a single bit each time, but for
@@ -597,7 +605,9 @@ int netlbl_secattr_catmap_setrng(struct netlbl_lsm_secattr_catmap *catmap,
                        iter = iter->next;
                        iter_max_spot = iter->startbit + NETLBL_CATMAP_SIZE;
                }
-               ret_val = netlbl_secattr_catmap_setbit(iter, spot, flags);
+               ret_val = netlbl_secattr_catmap_setbit(&iter, spot, flags);
+               if (iter->startbit < orig_spot)
+                       *catmap = iter;
        }
 
        return ret_val;

diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 62df845d861d582ae8ee8f23ddf9ef55b3d361f7..17da82f39ce7ede0a4470f13c3b2733710198991 100644 (file)
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -467,7 +467,7 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
                for (m = 0x80; m != 0; m >>= 1, cat++) {
                        if ((m & *cp) == 0)
                                continue;
-                       rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
+                       rc = netlbl_secattr_catmap_setbit(&sap->attr.mls.cat,
                                                          cat, GFP_ATOMIC);
                        if (rc < 0) {
                                netlbl_secattr_catmap_free(sap->attr.mls.cat);