When scsi_init_sense_cache(host) is called concurrently from different
hosts, each code path may see that the cache isn't created, then try
to create a new one, then the created sense cache may be overrided and
leaked.
Fixes the issue by moving 'mutex_lock(&scsi_sense_cache_mutex)' before
scsi_select_sense_cache().
Fixes: 0a6ac4ee7c21 ("scsi: respect unchecked_isa_dma for blk-mq")
Cc: Stable <stable@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Ewan D. Milne <emilne@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e07a376a8c38..7493680ec104 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -72,11 +72,11 @@ int scsi_init_sense_cache(struct Scsi_Host *shost)
struct kmem_cache *cache;
int ret = 0;
+ mutex_lock(&scsi_sense_cache_mutex);
cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
if (cache)
- return 0;
+ goto exit;
- mutex_lock(&scsi_sense_cache_mutex);
if (shost->unchecked_isa_dma) {
scsi_sense_isadma_cache =
kmem_cache_create("scsi_sense_cache(DMA)",
@@ -92,7 +92,7 @@ int scsi_init_sense_cache(struct Scsi_Host *shost)
if (!scsi_sense_cache)
ret = -ENOMEM;
}
-
+ exit:
mutex_unlock(&scsi_sense_cache_mutex);
return ret;
}
--
2.20.1
