From: Dan Carpenter <dan.carpenter@oracle.com>
To: kernel-janitors@vger.kernel.org
Subject: re: blkcg: fix blkcg_policy_data allocation bug
Date: Mon, 20 Jul 2015 14:54:36 +0000 [thread overview]
Message-ID: <20150720145436.GA19257@mwanda> (raw)
Hello Tejun Heo,
The patch 06b285bd1125: "blkcg: fix blkcg_policy_data allocation bug"
from Jul 9, 2015, leads to the following static checker warning:
block/blk-cgroup.c:1219 blkcg_policy_register()
error: double unlock 'mutex:&blkcg_pol_mutex'
block/blk-cgroup.c
1184 /* allocate and install cpd's */
1185 if (pol->cpd_size) {
1186 list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
1187 struct blkcg_policy_data *cpd;
1188
1189 cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
1190 if (!cpd) {
1191 mutex_unlock(&blkcg_pol_mutex);
^^^^^^^^^^^^^^^
Free.
1192 goto err_free_cpds;
1193 }
1194
1195 blkcg->pd[pol->plid] = cpd;
1196 cpd->plid = pol->plid;
1197 pol->cpd_init_fn(blkcg);
1198 }
1199 }
1200
1201 mutex_unlock(&blkcg_pol_mutex);
1202
1203 /* everything is in place, add intf files for the new policy */
1204 if (pol->cftypes)
1205 WARN_ON(cgroup_add_legacy_cftypes(&blkio_cgrp_subsys,
1206 pol->cftypes));
1207 mutex_unlock(&blkcg_pol_register_mutex);
1208 return 0;
1209
1210 err_free_cpds:
1211 if (pol->cpd_size) {
1212 list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
1213 kfree(blkcg->pd[pol->plid]);
1214 blkcg->pd[pol->plid] = NULL;
1215 }
1216 }
1217 blkcg_policy[pol->plid] = NULL;
1218 err_unlock:
1219 mutex_unlock(&blkcg_pol_mutex);
^^^^^^^^^^^^^^^
Double free.
1220 mutex_unlock(&blkcg_pol_register_mutex);
1221 return ret;
1222 }
1223 EXPORT_SYMBOL_GPL(blkcg_policy_register);
regards,
dan carpenter
next reply other threads:[~2015-07-20 14:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-20 14:54 Dan Carpenter [this message]
2015-07-21 15:06 ` [PATCH block/for-linus] blkcg: fix double unlock in blkcg_policy_register() error path Tejun Heo
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