scsi: snic: Fix possible UAF in snic_tgt_create()

Smatch reports a warning as follows:

drivers/scsi/snic/snic_disc.c:307 snic_tgt_create() warn:
  '&tgt->list' not removed from list

If device_add() fails in snic_tgt_create(), tgt will be freed, but
tgt->list will not be removed from snic->disc.tgt_list, then list traversal
may cause UAF.

Remove from snic->disc.tgt_list before free().

Fixes: c8806b6c9e82 ("snic: driver for Cisco SCSI HBA")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221117035100.2944812-1-cuigaosheng1@huawei.com
Acked-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/snic/snic_disc.c b/drivers/scsi/snic/snic_disc.c
index 9b2b5f8c23b9a3d628c7c50067dbb5fd4c762ce2..8fbf3c1b1311d805173e130101abb6a527ccf3fd 100644 (file)
--- a/drivers/scsi/snic/snic_disc.c
+++ b/drivers/scsi/snic/snic_disc.c
@@ -304,6 +304,9 @@ snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid)
                              ret);
 
                put_device(&snic->shost->shost_gendev);
+               spin_lock_irqsave(snic->shost->host_lock, flags);
+               list_del(&tgt->list);
+               spin_unlock_irqrestore(snic->shost->host_lock, flags);
                kfree(tgt);
                tgt = NULL;