Re: [PATCH] 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. An AUDIT_LOST_RESET message will be queued to the listening audit daemon. The message will be similar to a CONFIG_CHANGE message with the fields "lost=0" and "old=" containing the value of audit_lost at reset ending with a successful result code. See: https://github.com/linux-audit/audit-kernel/issues/3 Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- v3: Switch, from returing a message to the initiating process, to queueing the message for the audit log. v2: Switch from AUDIT_GET to AUDIT_SET, adding a +ve return code and sending a dedicated AUDIT_LOST_RESET message. --- include/uapi/linux/audit.h | 2 ++ kernel/audit.c | 16 +++++++++++++++- 2 files changed, 17 insertions(+), 1 deletions(-) diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index 208df7b..6d38bff 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -70,6 +70,7 @@ #define AUDIT_TTY_SET 1017 /* Set TTY auditing status */ #define AUDIT_SET_FEATURE 1018 /* Turn an audit feature on or off */ #define AUDIT_GET_FEATURE 1019 /* Get which features are enabled */ +#define AUDIT_LOST_RESET 1020 /* Reset the audit_lost value */ #define AUDIT_FIRST_USER_MSG 1100 /* Userspace messages mostly uninteresting to kernel */ #define AUDIT_USER_AVC 1107 /* We filter this differently */ @@ -325,6 +326,7 @@ 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 diff --git a/kernel/audit.c b/kernel/audit.c index f1ca116..441e8c0 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -122,7 +122,7 @@ 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; @@ -920,6 +920,20 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err < 0) return err; } + if (s.mask == AUDIT_STATUS_LOST) { + struct audit_buffer *ab; + u32 lost = atomic_xchg(&audit_lost, 0); + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOST_RESET); + if (unlikely(!ab)) + return lost;

+ audit_log_format(ab, "lost=0 old=%u", lost); + audit_log_session_info(ab); + audit_log_task_context(ab); + audit_log_format(ab, " res=1");

+ audit_log_end(ab); + return lost; + } break; } case AUDIT_GET_FEATURE: -- 1.7.1 -- Linux-audit mailing list Linux-audit(a)redhat.com https://www.redhat.com/mailman/listinfo/linux-audit