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authorPaolo Abeni <pabeni@redhat.com>2020-05-12 14:43:14 +0200
committerDavid S. Miller <davem@davemloft.net>2020-05-12 18:12:40 -0700
commiteead1c2ea2509fd754c6da893a94f0e69e83ebe4 (patch)
tree74a6833236e82b1de6ec523ef9ae7e3bde1250fa
parent24adbc1676af4e134e709ddc7f34cf2adc2131e4 (diff)
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netlabel: cope with NULL catmap
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>
-rw-r--r--net/ipv4/cipso_ipv4.c6
-rw-r--r--net/ipv6/calipso.c3
-rw-r--r--net/netlabel/netlabel_kapi.c6
3 files changed, 12 insertions, 3 deletions
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 0bd10a1f477f..a23094b050f8 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1258,7 +1258,8 @@ 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;
@@ -1439,7 +1440,8 @@ 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 221c81f85cbf..8d3f66c310db 100644
--- a/net/ipv6/calipso.c
+++ b/net/ipv6/calipso.c
@@ -1047,7 +1047,8 @@ 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 409a3ae47ce2..5e1239cef000 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -734,6 +734,12 @@ 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;