From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maurizio Lombardi Date: Wed, 07 Oct 2020 14:53:25 +0000 Subject: [PATCH 1/2] target: iscsi: prevent a race condition in iscsit_unmap_cmd() Message-Id: <20201007145326.56850-2-mlombard@redhat.com> List-Id: References: <20201007145326.56850-1-mlombard@redhat.com> In-Reply-To: <20201007145326.56850-1-mlombard@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: martin.petersen@oracle.com Cc: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, bvanassche@acm.org, michael.christie@oracle.com A potential race condition may occur in iscsit_unmap_cmd() if the __iscsit_free_cmd() function is called by two different threads. This patch adds a spinlock to serialize the calls to iscsit_unmap_cmd() Signed-off-by: Maurizio Lombardi --- drivers/target/iscsi/iscsi_target_login.c | 1 + drivers/target/iscsi/iscsi_target_util.c | 5 ++++- include/target/iscsi/iscsi_target_core.h | 1 + 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 893d1b406c29..e16ceee87bba 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -1110,6 +1110,7 @@ static struct iscsi_conn *iscsit_alloc_conn(struct iscsi_np *np) spin_lock_init(&conn->nopin_timer_lock); spin_lock_init(&conn->response_queue_lock); spin_lock_init(&conn->state_lock); + spin_lock_init(&conn->unmap_cmd_lock); timer_setup(&conn->nopin_response_timer, iscsit_handle_nopin_response_timeout, 0); diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 45ba07c6ec27..3082f5bde9fa 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -755,8 +755,11 @@ void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool check_queues) iscsit_remove_cmd_from_response_queue(cmd, conn); } - if (conn && conn->conn_transport->iscsit_unmap_cmd) + if (conn && conn->conn_transport->iscsit_unmap_cmd) { + spin_lock(&conn->unmap_cmd_lock); conn->conn_transport->iscsit_unmap_cmd(conn, cmd); + spin_unlock(&conn->unmap_cmd_lock); + } } void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown) diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h index 1eccb2ac7d02..ae7ac0134c8c 100644 --- a/include/target/iscsi/iscsi_target_core.h +++ b/include/target/iscsi/iscsi_target_core.h @@ -575,6 +575,7 @@ struct iscsi_conn { spinlock_t nopin_timer_lock; spinlock_t response_queue_lock; spinlock_t state_lock; + spinlock_t unmap_cmd_lock; /* libcrypto RX and TX contexts for crc32c */ struct ahash_request *conn_rx_hash; struct ahash_request *conn_tx_hash; -- 2.26.2