From: Mike Christie <michael.christie@xxxxxxxxxx>
[ Upstream commit 395cee83d02de3073211b04fc85724f4abc663ad ]
This fixes a bug added in commit f36199355c64 ("scsi: target: iscsi: Fix
cmd abort fabric stop race").
If we have multiple sessions to the same se_device we can hit a race where
a LUN_RESET on one session cleans up the se_cmds from under another
session which is being closed. This results in the closing session freeing
its conn/session structs while they are still in use.
The bug is:
1. Session1 has IO se_cmd1.
2. Session2 can also have se_cmds for I/O and optionally TMRs for ABORTS
but then gets a LUN_RESET.
3. The LUN_RESET on session2 sees the se_cmds on session1 and during the
drain stages marks them all with CMD_T_ABORTED.
4. session1 is now closed so iscsit_release_commands_from_conn() only sees
se_cmds with the CMD_T_ABORTED bit set and returns immediately even
though we have outstanding commands.
5. session1's connection and session are freed.
6. The backend request for se_cmd1 completes and it accesses the freed
connection/session.
This hooks the iscsit layer into the cmd counter code, so we can wait for
all outstanding se_cmds before freeing the connection.
Fixes: f36199355c64 ("scsi: target: iscsi: Fix cmd abort fabric stop race")
Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230319015620.96006-6-michael.christie@xxxxxxxxxx
Reviewed-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 11115c2078446..83b0071412294 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4245,6 +4245,16 @@ static void iscsit_release_commands_from_conn(struct iscsit_conn *conn)
iscsit_free_cmd(cmd, true);
}
+
+ /*
+ * Wait on commands that were cleaned up via the aborted_task path.
+ * LLDs that implement iscsit_wait_conn will already have waited for
+ * commands.
+ */
+ if (!conn->conn_transport->iscsit_wait_conn) {
+ target_stop_cmd_counter(conn->cmd_cnt);
+ target_wait_for_cmds(conn->cmd_cnt);
+ }
}
static void iscsit_stop_timers_for_cmds(
--
2.39.2
