This is a note to let you know that I've just added the patch titled audit: Allow auditd to set pid to 0 to end auditing to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: audit-allow-auditd-to-set-pid-to-0-to-end-auditing.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Dec 12 10:32:42 CET 2017 From: Steve Grubb <sgrubb@xxxxxxxxxx> Date: Tue, 17 Oct 2017 18:29:22 -0400 Subject: audit: Allow auditd to set pid to 0 to end auditing From: Steve Grubb <sgrubb@xxxxxxxxxx> [ Upstream commit 33e8a907804428109ce1d12301c3365d619cc4df ] The API to end auditing has historically been for auditd to set the pid to 0. This patch restores that functionality. See: https://github.com/linux-audit/audit-kernel/issues/69 Reviewed-by: Richard Guy Briggs <rgb@xxxxxxxxxx> Signed-off-by: Steve Grubb <sgrubb@xxxxxxxxxx> Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/audit.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1197,25 +1197,28 @@ static int audit_receive_msg(struct sk_b pid_t auditd_pid; struct pid *req_pid = task_tgid(current); - /* sanity check - PID values must match */ - if (new_pid != pid_vnr(req_pid)) + /* Sanity check - PID values must match. Setting + * pid to 0 is how auditd ends auditing. */ + if (new_pid && (new_pid != pid_vnr(req_pid))) return -EINVAL; /* test the auditd connection */ audit_replace(req_pid); auditd_pid = auditd_pid_vnr(); - /* only the current auditd can unregister itself */ - if ((!new_pid) && (new_pid != auditd_pid)) { - audit_log_config_change("audit_pid", new_pid, - auditd_pid, 0); - return -EACCES; - } - /* replacing a healthy auditd is not allowed */ - if (auditd_pid && new_pid) { - audit_log_config_change("audit_pid", new_pid, - auditd_pid, 0); - return -EEXIST; + if (auditd_pid) { + /* replacing a healthy auditd is not allowed */ + if (new_pid) { + audit_log_config_change("audit_pid", + new_pid, auditd_pid, 0); + return -EEXIST; + } + /* only current auditd can unregister itself */ + if (pid_vnr(req_pid) != auditd_pid) { + audit_log_config_change("audit_pid", + new_pid, auditd_pid, 0); + return -EACCES; + } } if (new_pid) { Patches currently in stable-queue which might be from sgrubb@xxxxxxxxxx are queue-4.14/audit-allow-auditd-to-set-pid-to-0-to-end-auditing.patch