The backlog cannot be consumed when audit_log_start is running on auditd
even if audit_log_start calls wait_for_auditd to consume it.
The situation is a deadlock because only auditd can consume the backlog.
If the other process needs to send the backlog, it can be also stopped
by the deadlock.
So, audit_log_start running on auditd should not stop.
You can see the deadlock with the following reproducer:
# auditctl -a exit,always -S all
# reboot
Signed-off-by: Toshiyuki Okajima <toshi.okaj...@jp.fujitsu.com>
Cc: gaof...@cn.fujitsu.com
---
kernel/audit.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index 7b0e23a..ce1fb38 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1098,6 +1098,9 @@ struct audit_buffer *audit_log_start(struct audit_context
*ctx, gfp_t gfp_mask,
int reserve;
unsigned long timeout_start = jiffies;
+ if (audit_pid && audit_pid == current->pid)
+ gfp_mask &= ~__GFP_WAIT;
+
if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
--
1.5.5.6
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