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| author | Konstantin Andreev <andreev@swemel.ru> | 2025-01-17 02:40:34 +0300 |
|---|---|---|
| committer | Casey Schaufler <casey@schaufler-ca.com> | 2025-02-16 14:17:55 -0800 |
| commit | a158a937d864d0034fea14913c1f09c6d5f574b8 (patch) | |
| tree | 68e06ccc84ba68b508ffc8e57d8a2cf45c78f949 /security | |
| parent | c7fb50cecff9cad19fdac5b37337eae4e42b94c7 (diff) | |
| download | linux-a158a937d864d0034fea14913c1f09c6d5f574b8.tar.gz linux-a158a937d864d0034fea14913c1f09c6d5f574b8.tar.bz2 linux-a158a937d864d0034fea14913c1f09c6d5f574b8.zip | |
smack: recognize ipv4 CIPSO w/o categories
If SMACK label has CIPSO representation w/o categories, e.g.:
| # cat /smack/cipso2
| foo 10
| @ 250/2
| ...
then SMACK does not recognize such CIPSO in input ipv4 packets
and substitues '*' label instead. Audit records may look like
| lsm=SMACK fn=smack_socket_sock_rcv_skb action=denied
| subject="*" object="_" requested=w pid=0 comm="swapper/1" ...
This happens in two steps:
1) security/smack/smackfs.c`smk_set_cipso
does not clear NETLBL_SECATTR_MLS_CAT
from (struct smack_known *)skp->smk_netlabel.flags
on assigning CIPSO w/o categories:
| rcu_assign_pointer(skp->smk_netlabel.attr.mls.cat, ncats.attr.mls.cat);
| skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl;
2) security/smack/smack_lsm.c`smack_from_secattr
can not match skp->smk_netlabel with input packet's
struct netlbl_lsm_secattr *sap
because sap->flags have not NETLBL_SECATTR_MLS_CAT (what is correct)
but skp->smk_netlabel.flags have (what is incorrect):
| if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
| if ((skp->smk_netlabel.flags &
| NETLBL_SECATTR_MLS_CAT) == 0)
| found = 1;
| break;
| }
This commit sets/clears NETLBL_SECATTR_MLS_CAT in
skp->smk_netlabel.flags according to the presense of CIPSO categories.
The update of smk_netlabel is not atomic, so input packets processing
still may be incorrect during short time while update proceeds.
Signed-off-by: Konstantin Andreev <andreev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/smack/smackfs.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 2802c480521c..90a67e410808 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -906,6 +906,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, if (rc >= 0) { old_cat = skp->smk_netlabel.attr.mls.cat; rcu_assign_pointer(skp->smk_netlabel.attr.mls.cat, ncats.attr.mls.cat); + if (ncats.attr.mls.cat) + skp->smk_netlabel.flags |= NETLBL_SECATTR_MLS_CAT; + else + skp->smk_netlabel.flags &= ~(u32)NETLBL_SECATTR_MLS_CAT; skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl; synchronize_rcu(); netlbl_catmap_free(old_cat); |