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| author |   Ming Lei <ming.lei@redhat.com> | 2019-07-12 10:08:19 +0800 |
|---|---|---|
| committer |   Martin K. Petersen <martin.petersen@oracle.com> | 2019-07-16 22:39:24 -0400 |
| commit | f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc (patch) | |
| tree | ca8a8951347a3b5bbba448d80269476271ed064b /drivers/scsi | |
| parent | scsi: sd_zbc: Fix compilation warning (diff) | |
| download | linux-dev-f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc.tar.xz linux-dev-f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc.zip | |
scsi: core: Fix race on creating sense cache
When scsi_init_sense_cache(host) is called concurrently from different
hosts, each code path may find that no cache has been created and
allocate a new one. The lack of locking can lead to potentially
overriding a cache allocated by a different host.
Fix 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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index ae1c989ef08e..420e2354b36b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -84,11 +84,11 @@ 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)", @@ -104,7 +104,7 @@ int scsi_init_sense_cache(struct Scsi_Host *shost) if (!scsi_sense_cache) ret = -ENOMEM; } - + exit: mutex_unlock(&scsi_sense_cache_mutex); return ret; } |