diff mbox series

[net-next,v2,2/2] net: sched: htb: remove redundant resource cleanup in htb_init()

Message ID 20220902083430.24378-3-shaozhengchao@huawei.com (mailing list archive)
State Accepted
Commit d59f4e1d1fe785e85c33f62136d93c8ea429442f
Delegated to: Netdev Maintainers
Headers show
Series net: sched: remove redundant resource cleanup when init() fails | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 1 this patch: 1
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 66 lines checked
netdev/kdoc success Errors and warnings before: 1 this patch: 1
netdev/source_inline success Was 0 now: 0

Commit Message

shaozhengchao Sept. 2, 2022, 8:34 a.m. UTC 
If htb_init() fails, qdisc_create() invokes htb_destroy() to clear
resources. Therefore, remove redundant resource cleanup in htb_init().

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
---
v1: rebase
---
 net/sched/sch_htb.c | 36 +++++++++---------------------------
 1 file changed, 9 insertions(+), 27 deletions(-)
diff mbox series

Patch

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index dbbb276aecb3..78d0c7549c74 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1102,7 +1102,7 @@  static int htb_init(struct Qdisc *sch, struct nlattr *opt,
 
 	err = qdisc_class_hash_init(&q->clhash);
 	if (err < 0)
-		goto err_free_direct_qdiscs;
+		return err;
 
 	if (tb[TCA_HTB_DIRECT_QLEN])
 		q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]);
@@ -1123,8 +1123,7 @@  static int htb_init(struct Qdisc *sch, struct nlattr *opt,
 		qdisc = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
 					  TC_H_MAKE(sch->handle, 0), extack);
 		if (!qdisc) {
-			err = -ENOMEM;
-			goto err_free_qdiscs;
+			return -ENOMEM;
 		}
 
 		htb_set_lockdep_class_child(qdisc);
@@ -1142,7 +1141,7 @@  static int htb_init(struct Qdisc *sch, struct nlattr *opt,
 	};
 	err = htb_offload(dev, &offload_opt);
 	if (err)
-		goto err_free_qdiscs;
+		return err;
 
 	/* Defer this assignment, so that htb_destroy skips offload-related
 	 * parts (especially calling ndo_setup_tc) on errors.
@@ -1150,22 +1149,6 @@  static int htb_init(struct Qdisc *sch, struct nlattr *opt,
 	q->offload = true;
 
 	return 0;
-
-err_free_qdiscs:
-	for (ntx = 0; ntx < q->num_direct_qdiscs && q->direct_qdiscs[ntx];
-	     ntx++)
-		qdisc_put(q->direct_qdiscs[ntx]);
-
-	qdisc_class_hash_destroy(&q->clhash);
-	/* Prevent use-after-free and double-free when htb_destroy gets called.
-	 */
-	q->clhash.hash = NULL;
-	q->clhash.hashsize = 0;
-
-err_free_direct_qdiscs:
-	kfree(q->direct_qdiscs);
-	q->direct_qdiscs = NULL;
-	return err;
 }
 
 static void htb_attach_offload(struct Qdisc *sch)
@@ -1688,13 +1671,12 @@  static void htb_destroy(struct Qdisc *sch)
 	qdisc_class_hash_destroy(&q->clhash);
 	__qdisc_reset_queue(&q->direct_queue);
 
-	if (!q->offload)
-		return;
-
-	offload_opt = (struct tc_htb_qopt_offload) {
-		.command = TC_HTB_DESTROY,
-	};
-	htb_offload(dev, &offload_opt);
+	if (q->offload) {
+		offload_opt = (struct tc_htb_qopt_offload) {
+			.command = TC_HTB_DESTROY,
+		};
+		htb_offload(dev, &offload_opt);
+	}
 
 	if (!q->direct_qdiscs)
 		return;