From 677264e8fb73ea35a508700e19ce76c527576d1c Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Fri, 28 Jun 2013 13:47:07 -0700 Subject: Smack: network label match fix The Smack code that matches incoming CIPSO tags with Smack labels reaches through the NetLabel interfaces and compares the network data with the CIPSO header associated with a Smack label. This was done in a ill advised attempt to optimize performance. It works so long as the categories fit in a single capset, but this isn't always the case. This patch changes the Smack code to use the appropriate NetLabel interfaces to compare the incoming CIPSO header with the CIPSO header associated with a label. It will always match the CIPSO headers correctly. Targeted for git://git.gitorious.org/smack-next/kernel.git Signed-off-by: Casey Schaufler --- security/smack/smack.h | 8 ++++++-- security/smack/smack_lsm.c | 30 ++++++++++++++++++++++++------ security/smack/smackfs.c | 2 +- 3 files changed, 31 insertions(+), 9 deletions(-) diff --git a/security/smack/smack.h b/security/smack/smack.h index e80597a3048a..076b8e8a51ab 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -168,9 +168,13 @@ struct smk_port_label { #define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */ #define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ #define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */ -#define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ #define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ -#define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ +/* + * CIPSO 2.2 standard is 239, but Smack wants to use the + * categories in a structured way that limits the value to + * the bits in 23 bytes, hence the unusual number. + */ +#define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */ /* * Flag for transmute access diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index ce000a81caf7..19204e11c02c 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3066,6 +3066,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, { struct smack_known *skp; int found = 0; + int acat; + int kcat; if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { /* @@ -3082,12 +3084,28 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, list_for_each_entry(skp, &smack_known_list, list) { if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) continue; - if (memcmp(sap->attr.mls.cat, - skp->smk_netlabel.attr.mls.cat, - SMK_CIPSOLEN) != 0) - continue; - found = 1; - break; + /* + * Compare the catsets. Use the netlbl APIs. + */ + if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { + if ((skp->smk_netlabel.flags & + NETLBL_SECATTR_MLS_CAT) == 0) + found = 1; + break; + } + for (acat = -1, kcat = -1; acat == kcat; ) { + acat = netlbl_secattr_catmap_walk( + sap->attr.mls.cat, acat + 1); + kcat = netlbl_secattr_catmap_walk( + skp->smk_netlabel.attr.mls.cat, + kcat + 1); + if (acat < 0 || kcat < 0) + break; + } + if (acat == kcat) { + found = 1; + break; + } } rcu_read_unlock(); diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 269b270c6473..a07e93f00a0f 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -890,7 +890,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, for (i = 0; i < catlen; i++) { rule += SMK_DIGITLEN; ret = sscanf(rule, "%u", &cat); - if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL) + if (ret != 1 || cat > SMACK_CIPSO_MAXCATNUM) goto out; smack_catset_bit(cat, mapcatset); -- cgit v1.2.3-58-ga151