From: Paolo Abeni <[email protected]> [ 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 <[email protected]> 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 <[email protected]> Acked-by: Paul Moore <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/ipv4/cipso_ipv4.c | 6 ++++-- net/netlabel/netlabel_kapi.c | 6 ++++++ 2 files changed, 10 insertions(+), 2 deletions(-) --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -1343,7 +1343,8 @@ static int cipso_v4_parsetag_rbm(const s return ret_val; } - secattr->flags |= NETLBL_SECATTR_MLS_CAT; + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; } return 0; @@ -1524,7 +1525,8 @@ static int cipso_v4_parsetag_rng(const s return ret_val; } - secattr->flags |= NETLBL_SECATTR_MLS_CAT; + if (secattr->attr.mls.cat) + secattr->flags |= NETLBL_SECATTR_MLS_CAT; } return 0; --- a/net/netlabel/netlabel_kapi.c +++ b/net/netlabel/netlabel_kapi.c @@ -605,6 +605,12 @@ int netlbl_catmap_getlong(struct netlbl_ 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;
