From 16870b7ba2855204af532c23fa973d530f4959b6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Fri, 29 Sep 2017 16:03:24 -0700 Subject: [PATCH] target: Fix caw_sem leak in transport_generic_request_failure commit fd2f928b0ddd2fe8876d4f1344df2ace2b715a4d upstream. With the recent addition of transport_check_aborted_status() within transport_generic_request_failure() to avoid sending a SCSI status exception after CMD_T_ABORTED w/ TAS=1 has occured, it introduced a COMPARE_AND_WRITE early failure regression. Namely when COMPARE_AND_WRITE fails and se_device->caw_sem has been taken by sbc_compare_and_write(), if the new check for transport_check_aborted_status() returns true and exits, cmd->transport_complete_callback() -> compare_and_write_post() is skipped never releasing se_device->caw_sem. This regression was originally introduced by: commit e3b88ee95b4e4bf3e9729a4695d695b9c7c296c8 Author: Bart Van Assche Date: Tue Feb 14 16:25:45 2017 -0800 target: Fix handling of aborted failed commands To address this bug, move the transport_check_aborted_status() call after transport_complete_task_attr() and cmd->transport_complete_callback(). Cc: Mike Christie Cc: Hannes Reinecke Cc: Bart Van Assche Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_transport.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 576d081325f4..953b99d8654c 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1730,9 +1730,6 @@ void transport_generic_request_failure(struct se_cmd *cmd, { int ret = 0, post_ret = 0; - if (transport_check_aborted_status(cmd, 1)) - return; - pr_debug("-----[ Storage Engine Exception; sense_reason %d\n", sense_reason); target_show_cmd("-----[ ", cmd); @@ -1741,6 +1738,7 @@ void transport_generic_request_failure(struct se_cmd *cmd, * For SAM Task Attribute emulation for failed struct se_cmd */ transport_complete_task_attr(cmd); + /* * Handle special case for COMPARE_AND_WRITE failure, where the * callback is expected to drop the per device ->caw_sem. @@ -1749,6 +1747,9 @@ void transport_generic_request_failure(struct se_cmd *cmd, cmd->transport_complete_callback) cmd->transport_complete_callback(cmd, false, &post_ret); + if (transport_check_aborted_status(cmd, 1)) + return; + switch (sense_reason) { case TCM_NON_EXISTENT_LUN: case TCM_UNSUPPORTED_SCSI_OPCODE: