diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2019-04-02 12:58:05 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-27 14:50:38 +0100 |
| commit | 047b402d1ba3dad09070e4fb9acaf2c38a89ef0d (patch) | |
| tree | 1429cb1b536333bdfa967d81a086018906582f7a | |
| parent | 4d1f1f1cb0607b4f25ce978ad5f19c8705643981 (diff) | |
scsi: target/core: Fix a race condition in the LUN lookup code
[ Upstream commit 63f7479439c95bcd49b7dd4af809862c316c71a3 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/target/target_core_device.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index e9ff2a7c0c0e..22e97a93728d 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; |