[PATCH v1] timekeeping: Unwind aux clock sysfs children on failure

[Yuho Choi]

tk_aux_sysfs_init() creates one child kobject per auxiliary clock. If a
later child or sysfs group creation fails, the current error path only
puts the parent kobjects and leaves earlier children and groups behind.

Store the child kobjects during init and remove the successfully created
groups and kobjects on failure.

Fixes: 7b5ab04f035f ("timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths")
Signed-off-by: Yuho Choi <dbgh9129@xxxxxxxxx>
---
 kernel/time/timekeeping.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index b1b5ec43c0f2..fe629a44d628 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -3313,7 +3313,9 @@ static const struct attribute_group aux_clock_enable_attr_group = {
 static int __init tk_aux_sysfs_init(void)
 {
 	struct kobject *auxo, *tko = kobject_create_and_add("time", kernel_kobj);
+	struct kobject *clks[MAX_AUX_CLOCKS];
 	int ret = -ENOMEM;
+	int i;
 
 	if (!tko)
 		return ret;
@@ -3322,21 +3324,28 @@ static int __init tk_aux_sysfs_init(void)
 	if (!auxo)
 		goto err_clean;
 
-	for (int i = 0; i < MAX_AUX_CLOCKS; i++) {
+	for (i = 0; i < MAX_AUX_CLOCKS; i++) {
 		char id[2] = { [0] = '0' + i, };
-		struct kobject *clk = kobject_create_and_add(id, auxo);
+		clks[i] = kobject_create_and_add(id, auxo);
 
-		if (!clk) {
+		if (!clks[i]) {
 			ret = -ENOMEM;
-			goto err_clean;
+			goto err_clks;
 		}
 
-		ret = sysfs_create_group(clk, &aux_clock_enable_attr_group);
+		ret = sysfs_create_group(clks[i], &aux_clock_enable_attr_group);
 		if (ret)
-			goto err_clean;
+			goto err_clk;
 	}
 	return 0;
 
+err_clk:
+	kobject_put(clks[i]);
+err_clks:
+	while (--i >= 0) {
+		sysfs_remove_group(clks[i], &aux_clock_enable_attr_group);
+		kobject_put(clks[i]);
+	}
 err_clean:
 	kobject_put(auxo);
 	kobject_put(tko);
-- 
2.43.0