| Message ID | 20190712020819.31935-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc |
| Headers | show |
| Series | [V2] scsi: fix race on creating sense cache | expand |
Ming, > 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(). Applied to 5.3/scsi-fixes, thanks!
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; }
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@vger.kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/scsi/scsi_lib.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)