Re: [PATCH V4] audit: add feature audit_lost reset

Add a method to reset the audit_lost value. An AUDIT_SET message with the AUDIT_STATUS_LOST flag set by itself will return a positive value repesenting the current audit_lost value and reset the counter to zero. If AUDIT_STATUS_LOST is not the only flag set, the reset command will be ignored. The value sent with the command is ignored. The return value will be the +ve lost value at reset time. An AUDIT_CONFIG_CHANGE message will be queued to the listening audit daemon. The message will be a standard CONFIG_CHANGE message with the fields "lost=0" and "old=" with the latter containing the value of audit_lost at reset time.

See: https://github.com/linux-audit/audit-kernel/issues/3 Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- There is a merge conflict anticipated with the exclude filter FEATURE_BITMAP patch (ghak5) v2: Switch from AUDIT_GET to AUDIT_SET Remove AUDIT_FEATURE and AUDIT_FEATURE_BITMAP Return +ve lost value, reply AUDIT_LOST_RESET msg to sender v3: Switch, from reply to sender, to queue to audit log v4: Switch from LOST_RESET to CONFIG_CHANGE log msg Re-add AUDIT_FEATURE_BITMASK --- --- include/uapi/linux/audit.h | 6 +++++- kernel/audit.c | 8 +++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index c8dc97b..3f24110 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -326,15 +326,19 @@ enum { #define AUDIT_STATUS_RATE_LIMIT 0x0008 #define AUDIT_STATUS_BACKLOG_LIMIT 0x0010 #define AUDIT_STATUS_BACKLOG_WAIT_TIME 0x0020 +#define AUDIT_STATUS_LOST 0x0040 #define AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT 0x00000001 #define AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME 0x00000002 #define AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH 0x00000004 #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER 0x00000010 +#define AUDIT_FEATURE_BITMAP_LOST_RESET 0x00000020 + #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \ AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \ AUDIT_FEATURE_BITMAP_EXECUTABLE_PATH | \ - AUDIT_FEATURE_BITMAP_SESSIONID_FILTER) + AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \ + AUDIT_FEATURE_BITMAP_LOST_RESET) /* deprecated: AUDIT_VERSION_* */ #define AUDIT_VERSION_LATEST AUDIT_FEATURE_BITMAP_ALL diff --git a/kernel/audit.c b/kernel/audit.c index 57acf25..25dd70a 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -121,7 +121,7 @@ u32 audit_sig_sid = 0; 3) suppressed due to audit_rate_limit 4) suppressed due to audit_backlog_limit */ -static atomic_t audit_lost = ATOMIC_INIT(0); +static atomic_t audit_lost = ATOMIC_INIT(0); /* The netlink socket. */ static struct sock *audit_sock; @@ -1052,6 +1052,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err < 0) return err; } + if (s.mask == AUDIT_STATUS_LOST) { + u32 lost = atomic_xchg(&audit_lost, 0); + + audit_log_config_change("lost", 0, lost, 1); + return lost; + } break; } case AUDIT_GET_FEATURE: