From 7ff684a683d777c4956fce93e60accbab2bd7696 Mon Sep 17 00:00:00 2001
From: John Pittman <jpittman@redhat.com>
Date: Fri, 5 Apr 2019 17:42:45 -0400
Subject: [PATCH] null_blk: prevent crash from bad home_node value
At module load, if the selected home_node value is greater than
the available numa nodes, the system will crash in
__alloc_pages_nodemask() due to a bad paging request. Prevent this
user error crash by detecting the bad value, logging an error, and
setting g_home_node back to the default of NUMA_NO_NODE.
Signed-off-by: John Pittman <jpittman@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/block/null_blk_main.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index 417a9f15c1163..d7ac09c092f2a 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1748,6 +1748,11 @@ static int __init null_init(void)
return -EINVAL;
}
+ if (g_home_node != NUMA_NO_NODE && g_home_node >= nr_online_nodes) {
+ pr_err("null_blk: invalid home_node value\n");
+ g_home_node = NUMA_NO_NODE;
+ }
+
if (g_queue_mode == NULL_Q_RQ) {
pr_err("null_blk: legacy IO path no longer available\n");
return -EINVAL;
--
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