netlabel: cope with NULL catmap

[ Upstream commit eead1c2ea2509fd754c6da893a94f0e69e83ebe4 ]

The cipso and calipso code can set the MLS_CAT attribute on
successful parsing, even if the corresponding catmap has
not been allocated, as per current configuration and external
input.

Later, selinux code tries to access the catmap if the MLS_CAT flag
is present via netlbl_catmap_getlong(). That may cause null ptr
dereference while processing incoming network traffic.

Address the issue setting the MLS_CAT flag only if the catmap is
really allocated. Additionally let netlbl_catmap_getlong() cope
with NULL catmap.

Reported-by: Matthew Sheets <matthew.sheets@gd-ms.com>
Fixes: 4b8feff251da ("netlabel: fix the horribly broken catmap functions")
Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 1c21dc5d6dd4049c47f947ac727516500d534ff2..5535b722f66d67fb43e44124343e80283f613621 100644 (file)
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1272,7 +1272,8 @@ static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
                        return ret_val;
                }
 
-               secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+               if (secattr->attr.mls.cat)
+                       secattr->flags |= NETLBL_SECATTR_MLS_CAT;
        }
 
        return 0;
@@ -1453,7 +1454,8 @@ static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
                        return ret_val;
                }
 
-               secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+               if (secattr->attr.mls.cat)
+                       secattr->flags |= NETLBL_SECATTR_MLS_CAT;
        }
 
        return 0;

diff --git a/net/ipv6/calipso.c b/net/ipv6/calipso.c
index 1c0bb9fb76e61fa7d12317190ebac38847530858..70611784c071f9a7070efce6fd1e3e9a2e2a1cf9 100644 (file)
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -1061,7 +1061,8 @@ static int calipso_opt_getattr(const unsigned char *calipso,
                        goto getattr_return;
                }
 
-               secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+               if (secattr->attr.mls.cat)
+                       secattr->flags |= NETLBL_SECATTR_MLS_CAT;
        }
 
        secattr->type = NETLBL_NLTYPE_CALIPSO;

diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index ee3e5b6471a69ec0100ea9099dc2e8be24a4b024..15fe2120b31096983071f36ff2e066a8fb7d4443 100644 (file)
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -748,6 +748,12 @@ int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
        if ((off & (BITS_PER_LONG - 1)) != 0)
                return -EINVAL;
 
+       /* a null catmap is equivalent to an empty one */
+       if (!catmap) {
+               *offset = (u32)-1;
+               return 0;
+       }
+
        if (off < catmap->startbit) {
                off = catmap->startbit;
                *offset = off;