From: hubin <hubin73@huawei.com>
Date: Thu, 18 May 2023 08:14:41 +0000 (+0800)
Subject: ras-events: quit loop in read_ras_event when kbuf data is broken
X-Git-Tag: v0.8.1~84
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=794530fbf270eae9f6f43c6d0bbd3ec6f2b210f3;p=users%2Fmchehab%2Frasdaemon.git

ras-events: quit loop in read_ras_event when kbuf data is broken

when kbuf data is broken, kbuffer_next_event() may move kbuf->index back to
the current kbuf->index position, causing dead loop.

In this situation, rasdaemon will repeatedly parse an invalid event, and
print warning like "ug! negative record size -8!", pushing cpu utilization
rate to 100%.

when kbuf data is broken, discard current page and continue reading next page
kbuf.

Signed-off-by: hubin <hubin73@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
---

diff --git a/ras-events.c b/ras-events.c
index 2662467..fced7ab 100644
--- a/ras-events.c
+++ b/ras-events.c
@@ -512,6 +512,11 @@ static int read_ras_event_all_cpus(struct pthread_data *pdata,
 				kbuffer_load_subbuffer(kbuf, page);
 
 				while ((data = kbuffer_read_event(kbuf, &time_stamp))) {
+					if (kbuffer_curr_size(kbuf) < 0) {
+						log(TERM, LOG_ERR, "invalid kbuf data, discard\n");
+						break;
+					}
+
 					parse_ras_data(&pdata[i],
 						       kbuf, data, time_stamp);