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Commit fc09149d authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target: Fix free-after-use regression in PR unregister 



This patch addresses a >= v3.11 free-after-use regression
in core_scsi3_emulate_pro_register() that was introduced
in the following commit:

commit bc118fe4
Author: Andy Grover <agrover@redhat.com>
Date:   Thu May 16 10:41:04 2013 -0700

    target: Further refactoring of core_scsi3_emulate_pro_register()

To avoid the free-after-use, save an type value before hand, and
only call core_scsi3_put_pr_reg() with a valid *pr_reg.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Cc: Andy Grover <agrover@redhat.com>
Cc: <stable@vger.kernel.org> #3.11+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent b28a960c

drivers/target/target_core_pr.c

+7 −4
Original line number Diff line number Diff line
@@ -2009,7 +2009,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, 
	struct t10_reservation *pr_tmpl = &dev->t10_pr;

	unsigned char isid_buf[PR_REG_ISID_LEN], *isid_ptr = NULL;

	sense_reason_t ret = TCM_NO_SENSE;

	int pr_holder = 0;

	int pr_holder = 0, type;



	if (!se_sess || !se_lun) {

		pr_err("SPC-3 PR: se_sess || struct se_lun is NULL!\n");
@@ -2131,6 +2131,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, 
			ret = TCM_RESERVATION_CONFLICT;

			goto out;

		}

		type = pr_reg->pr_res_type;



		spin_lock(&pr_tmpl->registration_lock);

		/*
@@ -2161,6 +2162,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, 
		 * Release the calling I_T Nexus registration now..

		 */

		__core_scsi3_free_registration(cmd->se_dev, pr_reg, NULL, 1);

		pr_reg = NULL;



		/*

		 * From spc4r17, section 5.7.11.3 Unregistering
@@ -2174,8 +2176,8 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, 
		 * RESERVATIONS RELEASED.

		 */

		if (pr_holder &&

		    (pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||

		     pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {

		    (type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY ||

		     type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY)) {

			list_for_each_entry(pr_reg_p,

					&pr_tmpl->registration_list,

					pr_reg_list) {
@@ -2194,6 +2196,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key, 
	ret = core_scsi3_update_and_write_aptpl(dev, aptpl);



out:

	if (pr_reg)

		core_scsi3_put_pr_reg(pr_reg);

	return ret;

}