diff options
author | John Johansen <john.johansen@canonical.com> | 2020-11-17 01:38:16 -0800 |
---|---|---|
committer | John Johansen <john.johansen@canonical.com> | 2022-10-03 14:49:03 -0700 |
commit | e2967ede22978f132cd52929edff96c701bde0eb (patch) | |
tree | be2a22d52d6bd15e44ee25a507fb589d464951ff /security | |
parent | e48ffd24c1d87dba227225615790cd059a707adb (diff) | |
download | linux-stable-e2967ede22978f132cd52929edff96c701bde0eb.tar.gz linux-stable-e2967ede22978f132cd52929edff96c701bde0eb.tar.bz2 linux-stable-e2967ede22978f132cd52929edff96c701bde0eb.zip |
apparmor: compute policydb permission on profile load
Rather than computing policydb permissions for each access
permissions can be computed once on profile load and stored for lookup.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Diffstat (limited to 'security')
-rw-r--r-- | security/apparmor/apparmorfs.c | 2 | ||||
-rw-r--r-- | security/apparmor/include/perms.h | 13 | ||||
-rw-r--r-- | security/apparmor/include/policy.h | 1 | ||||
-rw-r--r-- | security/apparmor/label.c | 6 | ||||
-rw-r--r-- | security/apparmor/lib.c | 42 | ||||
-rw-r--r-- | security/apparmor/mount.c | 53 | ||||
-rw-r--r-- | security/apparmor/net.c | 2 | ||||
-rw-r--r-- | security/apparmor/policy.c | 2 | ||||
-rw-r--r-- | security/apparmor/policy_unpack.c | 55 |
9 files changed, 90 insertions, 86 deletions
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 825b3093dcdd..117783779337 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -633,7 +633,7 @@ static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms, state = aa_dfa_match_len(dfa, profile->policy.start[0], match_str, match_len); if (state) - aa_compute_perms(dfa, state, &tmp); + tmp = *aa_lookup_perms(profile->policy.perms, state); } aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum_raw(perms, &tmp); diff --git a/security/apparmor/include/perms.h b/security/apparmor/include/perms.h index 13f20c598448..de9631edb1ff 100644 --- a/security/apparmor/include/perms.h +++ b/security/apparmor/include/perms.h @@ -133,6 +133,17 @@ extern struct aa_perms allperms; xcheck(fn_for_each((L1), (P), (FN1)), fn_for_each((L2), (P), (FN2))) +extern struct aa_perms default_perms; + +static inline struct aa_perms *aa_lookup_perms(struct aa_perms *perms, + unsigned int state) +{ + if (!(perms)) + return &default_perms; + + return &(perms[state]); +} + void aa_perm_mask_to_str(char *str, size_t str_size, const char *chrs, u32 mask); void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names, @@ -141,8 +152,6 @@ void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs, u32 chrsmask, const char * const *names, u32 namesmask); void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms); -void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, - struct aa_perms *perms); void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend); void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend); void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label, diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index 7882d5e5096b..0dec18cd95e5 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -77,6 +77,7 @@ enum profile_mode { struct aa_policydb { /* Generic policy DFA specific rule types will be subsections of it */ struct aa_dfa *dfa; + struct aa_perms *perms; unsigned int start[AA_CLASS_LAST + 1]; }; diff --git a/security/apparmor/label.c b/security/apparmor/label.c index 0f36ee907438..ddb04417bdab 100644 --- a/security/apparmor/label.c +++ b/security/apparmor/label.c @@ -1328,7 +1328,7 @@ next: if (!state) goto fail; } - aa_compute_perms(profile->policy.dfa, state, perms); + *perms = *aa_lookup_perms(profile->policy.perms, state); aa_apply_modes_to_perms(profile, perms); if ((perms->allow & request) != request) return -EACCES; @@ -1379,7 +1379,7 @@ static int label_components_match(struct aa_profile *profile, return 0; next: - aa_compute_perms(profile->policy.dfa, state, &tmp); + tmp = *aa_lookup_perms(profile->policy.perms, state); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); label_for_each_cont(i, label, tp) { @@ -1388,7 +1388,7 @@ next: state = match_component(profile, tp, start); if (!state) goto fail; - aa_compute_perms(profile->policy.dfa, state, &tmp); + tmp = *aa_lookup_perms(profile->policy.perms, state); aa_apply_modes_to_perms(profile, &tmp); aa_perms_accum(perms, &tmp); } diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c index 1c72a61108d3..505ef5848f7c 100644 --- a/security/apparmor/lib.c +++ b/security/apparmor/lib.c @@ -315,48 +315,6 @@ void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms) */ } -static u32 map_other(u32 x) -{ - return ((x & 0x3) << 8) | /* SETATTR/GETATTR */ - ((x & 0x1c) << 18) | /* ACCEPT/BIND/LISTEN */ - ((x & 0x60) << 19); /* SETOPT/GETOPT */ -} - -static u32 map_xbits(u32 x) -{ - return ((x & 0x1) << 7) | - ((x & 0x7e) << 9); -} - -void aa_compute_perms(struct aa_dfa *dfa, unsigned int state, - struct aa_perms *perms) -{ - /* This mapping is convulated due to history. - * v1-v4: only file perms - * v5: added policydb which dropped in perm user conditional to - * gain new perm bits, but had to map around the xbits because - * the userspace compiler was still munging them. - * v9: adds using the xbits in policydb because the compiler now - * supports treating policydb permission bits different. - * Unfortunately there is not way to force auditing on the - * perms represented by the xbits - */ - *perms = (struct aa_perms) { - .allow = dfa_user_allow(dfa, state) | - map_xbits(dfa_user_xbits(dfa, state)), - .audit = dfa_user_audit(dfa, state), - .quiet = dfa_user_quiet(dfa, state) | - map_xbits(dfa_other_xbits(dfa, state)), - }; - - /* for v5-v9 perm mapping in the policydb, the other set is used - * to extend the general perm set - */ - perms->allow |= map_other(dfa_other_allow(dfa, state)); - perms->audit |= map_other(dfa_other_audit(dfa, state)); - perms->quiet |= map_other(dfa_other_quiet(dfa, state)); -} - /** * aa_perms_accum_raw - accumulate perms with out masking off overlapping perms * @accum - perms struct to accumulate into diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index f61247241803..1e978c2b1ee4 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -203,25 +203,6 @@ static unsigned int match_mnt_flags(struct aa_dfa *dfa, unsigned int state, return state; } -/** - * compute_mnt_perms - compute mount permission associated with @state - * @dfa: dfa to match against (NOT NULL) - * @state: state match finished in - * - * Returns: mount permissions - */ -static struct aa_perms compute_mnt_perms(struct aa_dfa *dfa, - unsigned int state) -{ - struct aa_perms perms = { - .allow = dfa_user_allow(dfa, state), - .audit = dfa_user_audit(dfa, state), - .quiet = dfa_user_quiet(dfa, state), - }; - - return perms; -} - static const char * const mnt_info_table[] = { "match succeeded", "failed mntpnt match", @@ -236,50 +217,52 @@ static const char * const mnt_info_table[] = { * Returns 0 on success else element that match failed in, this is the * index into the mnt_info_table above */ -static int do_match_mnt(struct aa_dfa *dfa, unsigned int start, +static int do_match_mnt(struct aa_policydb *policy, unsigned int start, const char *mntpnt, const char *devname, const char *type, unsigned long flags, void *data, bool binary, struct aa_perms *perms) { unsigned int state; - AA_BUG(!dfa); + AA_BUG(!policy); + AA_BUG(!policy->dfa); + AA_BUG(!policy->perms); AA_BUG(!perms); - state = aa_dfa_match(dfa, start, mntpnt); - state = aa_dfa_null_transition(dfa, state); + state = aa_dfa_match(policy->dfa, start, mntpnt); + state = aa_dfa_null_transition(policy->dfa, state); if (!state) return 1; if (devname) - state = aa_dfa_match(dfa, state, devname); - state = aa_dfa_null_transition(dfa, state); + state = aa_dfa_match(policy->dfa, state, devname); + state = aa_dfa_null_transition(policy->dfa, state); if (!state) return 2; if (type) - state = aa_dfa_match(dfa, state, type); - state = aa_dfa_null_transition(dfa, state); + state = aa_dfa_match(policy->dfa, state, type); + state = aa_dfa_null_transition(policy->dfa, state); if (!state) return 3; - state = match_mnt_flags(dfa, state, flags); + state = match_mnt_flags(policy->dfa, state, flags); if (!state) return 4; - *perms = compute_mnt_perms(dfa, state); + *perms = *aa_lookup_perms(policy->perms, state); if (perms->allow & AA_MAY_MOUNT) return 0; /* only match data if not binary and the DFA flags data is expected */ if (data && !binary && (perms->allow & AA_MNT_CONT_MATCH)) { - state = aa_dfa_null_transition(dfa, state); + state = aa_dfa_null_transition(policy->dfa, state); if (!state) return 4; - state = aa_dfa_match(dfa, state, data); + state = aa_dfa_match(policy->dfa, state, data); if (!state) return 5; - *perms = compute_mnt_perms(dfa, state); + *perms = *aa_lookup_perms(policy->perms, state); if (perms->allow & AA_MAY_MOUNT) return 0; } @@ -341,7 +324,7 @@ static int match_mnt_path_str(struct aa_profile *profile, } error = -EACCES; - pos = do_match_mnt(profile->policy.dfa, + pos = do_match_mnt(&profile->policy, profile->policy.start[AA_CLASS_MOUNT], mntpnt, devname, type, flags, data, binary, &perms); if (pos) { @@ -601,7 +584,7 @@ static int profile_umount(struct aa_profile *profile, const struct path *path, state = aa_dfa_match(profile->policy.dfa, profile->policy.start[AA_CLASS_MOUNT], name); - perms = compute_mnt_perms(profile->policy.dfa, state); + perms = *aa_lookup_perms(profile->policy.perms, state); if (AA_MAY_UMOUNT & ~perms.allow) error = -EACCES; @@ -672,7 +655,7 @@ static struct aa_label *build_pivotroot(struct aa_profile *profile, new_name); state = aa_dfa_null_transition(profile->policy.dfa, state); state = aa_dfa_match(profile->policy.dfa, state, old_name); - perms = compute_mnt_perms(profile->policy.dfa, state); + perms = *aa_lookup_perms(profile->policy.perms, state); if (AA_MAY_PIVOTROOT & perms.allow) error = 0; diff --git a/security/apparmor/net.c b/security/apparmor/net.c index 7efe4d17273d..88e8a7ea54c0 100644 --- a/security/apparmor/net.c +++ b/security/apparmor/net.c @@ -125,7 +125,7 @@ int aa_profile_af_perm(struct aa_profile *profile, struct common_audit_data *sa, buffer[1] = cpu_to_be16((u16) type); state = aa_dfa_match_len(profile->policy.dfa, state, (char *) &buffer, 4); - aa_compute_perms(profile->policy.dfa, state, &perms); + perms = *aa_lookup_perms(profile->policy.perms, state); aa_apply_modes_to_perms(profile, &perms); return aa_check_perms(profile, &perms, request, sa, audit_net_cb); diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index e2d23cd85cd2..6c3086e2c820 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -233,7 +233,7 @@ void aa_free_profile(struct aa_profile *profile) aa_put_dfa(profile->xmatch); kvfree(profile->xmatch_perms); aa_put_dfa(profile->policy.dfa); - + kvfree(profile->policy.perms); if (profile->data) { rht = profile->data; profile->data = NULL; diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 44910c201c49..ed063385a83b 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -756,7 +756,7 @@ static struct aa_perms *compute_fperms(struct aa_dfa *dfa) state_count = dfa->tables[YYTD_ID_BASE]->td_lolen; /* DFAs are restricted from having a state_count of less than 2 */ - table = kvzalloc(state_count * 2 * sizeof(struct aa_perms), GFP_KERNEL); + table = kvcalloc(state_count * 2, sizeof(struct aa_perms), GFP_KERNEL); if (!table) return NULL; @@ -789,6 +789,54 @@ static struct aa_perms *compute_xmatch_perms(struct aa_dfa *xmatch) return perms_table; } +static u32 map_other(u32 x) +{ + return ((x & 0x3) << 8) | /* SETATTR/GETATTR */ + ((x & 0x1c) << 18) | /* ACCEPT/BIND/LISTEN */ + ((x & 0x60) << 19); /* SETOPT/GETOPT */ +} + +static struct aa_perms compute_perms_entry(struct aa_dfa *dfa, + unsigned int state) +{ + struct aa_perms perms = { }; + + perms.allow = dfa_user_allow(dfa, state); + perms.audit = dfa_user_audit(dfa, state); + perms.quiet = dfa_user_quiet(dfa, state); + + /* for v5 perm mapping in the policydb, the other set is used + * to extend the general perm set + */ + + perms.allow |= map_other(dfa_other_allow(dfa, state)); + perms.audit |= map_other(dfa_other_audit(dfa, state)); + perms.quiet |= map_other(dfa_other_quiet(dfa, state)); + + return perms; +} + +static struct aa_perms *compute_perms(struct aa_dfa *dfa) +{ + int state; + int state_count; + struct aa_perms *table; + + AA_BUG(!dfa); + + state_count = dfa->tables[YYTD_ID_BASE]->td_lolen; + /* DFAs are restricted from having a state_count of less than 2 */ + table = kvcalloc(state_count, sizeof(struct aa_perms), GFP_KERNEL); + if (!table) + return NULL; + + /* zero init so skip the trap state (state == 0) */ + for (state = 1; state < state_count; state++) + table[state] = compute_perms_entry(dfa, state); + + return table; +} + /** * unpack_profile - unpack a serialized profile * @e: serialized data extent information (NOT NULL) @@ -986,6 +1034,11 @@ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name) goto fail; } else profile->policy.dfa = aa_get_dfa(nulldfa); + profile->policy.perms = compute_perms(profile->policy.dfa); + if (!profile->policy.perms) { + info = "failed to remap policydb permission table"; + goto fail; + } /* get file rules */ profile->file.dfa = unpack_dfa(e); |