Implement container ID filtering using the AUDIT_CONTAINERID field name to send an 8-character string representing a u64 since the value field is only u32. Sending it as two u32 was considered, but gathering and comparing two fields was more complex. The feature indicator is AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER. This requires support from userspace to be useful. See: https://github.com/linux-audit/audit-userspace/issues/40 Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx> --- include/linux/audit.h | 1 + include/uapi/linux/audit.h | 5 ++++- kernel/audit.h | 1 + kernel/auditfilter.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++ kernel/auditsc.c | 3 +++ 5 files changed, 56 insertions(+), 1 deletion(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 3acbe9d..f10ca1b 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -76,6 +76,7 @@ struct audit_field { u32 type; union { u32 val; + u64 val64; kuid_t uid; kgid_t gid; struct { diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index e83ccbd..8443a8f 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -262,6 +262,7 @@ #define AUDIT_LOGINUID_SET 24 #define AUDIT_SESSIONID 25 /* Session ID */ #define AUDIT_FSTYPE 26 /* FileSystem Type */ +#define AUDIT_CONTAINERID 27 /* Container ID */ /* These are ONLY useful when checking * at syscall exit time (AUDIT_AT_EXIT). */ @@ -342,6 +343,7 @@ enum { #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER 0x00000010 #define AUDIT_FEATURE_BITMAP_LOST_RESET 0x00000020 #define AUDIT_FEATURE_BITMAP_FILTER_FS 0x00000040 +#define AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER 0x00000080 #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \ AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \ @@ -349,7 +351,8 @@ enum { AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND | \ AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \ AUDIT_FEATURE_BITMAP_LOST_RESET | \ - AUDIT_FEATURE_BITMAP_FILTER_FS) + AUDIT_FEATURE_BITMAP_FILTER_FS | \ + AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER) /* deprecated: AUDIT_VERSION_* */ #define AUDIT_VERSION_LATEST AUDIT_FEATURE_BITMAP_ALL diff --git a/kernel/audit.h b/kernel/audit.h index 214e149..aaa651a 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -234,6 +234,7 @@ static inline int audit_hash_ino(u32 ino) extern int audit_match_class(int class, unsigned syscall); extern int audit_comparator(const u32 left, const u32 op, const u32 right); +extern int audit_comparator64(const u64 left, const u32 op, const u64 right); extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right); extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right); extern int parent_len(const char *path); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index d7a807e..c4c8746 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -410,6 +410,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) /* FALL THROUGH */ case AUDIT_ARCH: case AUDIT_FSTYPE: + case AUDIT_CONTAINERID: if (f->op != Audit_not_equal && f->op != Audit_equal) return -EINVAL; break; @@ -584,6 +585,14 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, } entry->rule.exe = audit_mark; break; + case AUDIT_CONTAINERID: + if (f->val != sizeof(u64)) + goto exit_free; + str = audit_unpack_string(&bufp, &remain, f->val); + if (IS_ERR(str)) + goto exit_free; + f->val64 = ((u64 *)str)[0]; + break; } } @@ -666,6 +675,11 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) data->buflen += data->values[i] = audit_pack_string(&bufp, audit_mark_path(krule->exe)); break; + case AUDIT_CONTAINERID: + data->buflen += data->values[i] = sizeof(u64); + for (i = 0; i < sizeof(u64); i++) + ((char *)bufp)[i] = ((char *)&f->val64)[i]; + break; case AUDIT_LOGINUID_SET: if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) { data->fields[i] = AUDIT_LOGINUID; @@ -752,6 +766,10 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) if (!gid_eq(a->fields[i].gid, b->fields[i].gid)) return 1; break; + case AUDIT_CONTAINERID: + if (a->fields[i].val64 != b->fields[i].val64) + return 1; + break; default: if (a->fields[i].val != b->fields[i].val) return 1; @@ -1210,6 +1228,31 @@ int audit_comparator(u32 left, u32 op, u32 right) } } +int audit_comparator64(u64 left, u32 op, u64 right) +{ + switch (op) { + case Audit_equal: + return (left == right); + case Audit_not_equal: + return (left != right); + case Audit_lt: + return (left < right); + case Audit_le: + return (left <= right); + case Audit_gt: + return (left > right); + case Audit_ge: + return (left >= right); + case Audit_bitmask: + return (left & right); + case Audit_bittest: + return ((left & right) == right); + default: + BUG(); + return 0; + } +} + int audit_uid_comparator(kuid_t left, u32 op, kuid_t right) { switch (op) { @@ -1348,6 +1391,10 @@ int audit_filter(int msgtype, unsigned int listtype) result = audit_comparator(audit_loginuid_set(current), f->op, f->val); break; + case AUDIT_CONTAINERID: + result = audit_comparator64(audit_get_containerid(current), + f->op, f->val64); + break; case AUDIT_MSGTYPE: result = audit_comparator(msgtype, f->op, f->val); break; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 65be110..2bba324 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -614,6 +614,9 @@ static int audit_filter_rules(struct task_struct *tsk, case AUDIT_LOGINUID_SET: result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val); break; + case AUDIT_CONTAINERID: + result = audit_comparator64(audit_get_containerid(tsk), f->op, f->val64); + break; case AUDIT_SUBJ_USER: case AUDIT_SUBJ_ROLE: case AUDIT_SUBJ_TYPE: -- 1.8.3.1
