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authorBart Van Assche <bvanassche@acm.org>2019-04-02 22:58:05 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2019-04-13 03:20:05 +0300
commit63f7479439c95bcd49b7dd4af809862c316c71a3 (patch)
treec7c5509ade07fa7f5a6a01ff1bb7e40bfdeecb70 /drivers/target
parenta6a6d0589ac4ff3e1eb962f6c53e67d8f6386c18 (diff)
downloadlinux-63f7479439c95bcd49b7dd4af809862c316c71a3.tar.xz
scsi: target/core: Fix a race condition in the LUN lookup code
The rcu_dereference(deve->se_lun) expression occurs twice in the LUN lookup functions. Since these expressions are not serialized against deve->se_lun assignments each of these expressions may yield a different result. Avoid that the wrong LUN pointer is stored in se_cmd by reading deve->se_lun only once. Cc: Mike Christie <mchristi@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Fixes: 29a05deebf6c ("target: Convert se_node_acl->device_list[] to RCU hlist") # v4.10 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_device.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 1f8482b6473b..7eae1c823c4e 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -85,7 +85,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
goto out_unlock;
}
- se_cmd->se_lun = rcu_dereference(deve->se_lun);
+ se_cmd->se_lun = se_lun;
se_cmd->pr_res_key = deve->pr_res_key;
se_cmd->orig_fe_lun = unpacked_lun;
se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
@@ -176,7 +176,7 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd, u64 unpacked_lun)
goto out_unlock;
}
- se_cmd->se_lun = rcu_dereference(deve->se_lun);
+ se_cmd->se_lun = se_lun;
se_cmd->pr_res_key = deve->pr_res_key;
se_cmd->orig_fe_lun = unpacked_lun;
se_cmd->se_cmd_flags |= SCF_SE_LUN_CMD;