linux-kernel - [PATCH] timers/migration: Improve error handling and resource cleanup in tmigr_setup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20260204073337.57222-1-zhanxusheng@xiaomi.com>
Date: Wed,  4 Feb 2026 15:33:37 +0800
From: Zhan Xusheng <zhanxusheng1024@...il.com>
To: Frederic Weisbecker <frederic@...nel.org>
Cc: linux-kernel@...r.kernel.org,
	Zhan Xusheng <zhanxusheng@...omi.com>
Subject: [PATCH] timers/migration: Improve error handling and resource cleanup in tmigr_setup_groups

Introduce a new helper function `tmigr_clean_groups` to centralize
cleanup of groups when an error occurs. This simplifies the error
handling and ensures consistent resource management. Additionally,
redundant error checks and resource freeing logic were removed.

Signed-off-by: Zhan Xusheng <zhanxusheng@...omi.com>
---
 kernel/time/timer_migration.c | 37 +++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c
index 18dda1aa782d..a3b6b0af5900 100644
--- a/kernel/time/timer_migration.c
+++ b/kernel/time/timer_migration.c
@@ -1750,6 +1750,29 @@ static void tmigr_connect_child_parent(struct tmigr_group *child,
 	trace_tmigr_connect_child_parent(child);
 }
 
+/**
+ * tmigr_clean_groups - Clean up groups in the given level range and free memory
+ * @stack: The stack holding groups
+ * @start_lvl: The starting level to clean from
+ * @end_lvl: The ending level to clean up to
+ *
+ * This function iterates over the stack from start_lvl to end_lvl and removes the
+ * groups from the list and frees the allocated memory. It is used to clean up
+ * groups when an error occurs.
+ */
+static void tmigr_clean_groups(struct tmigr_group **stack,
+			       int start_lvl, int end_lvl)
+{
+	struct tmigr_group *group;
+	int i = end_lvl;
+
+	for (; i >= start_lvl; i--) {
+		group = stack[i];
+		list_del(&group->list);
+		kfree(group);
+	}
+}
+
 static int tmigr_setup_groups(unsigned int cpu, unsigned int node,
 			      struct tmigr_group *start, bool activate)
 {
@@ -1774,7 +1797,10 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node,
 		if (IS_ERR(group)) {
 			err = PTR_ERR(group);
 			i--;
-			break;
+			/* Clean up already allocated groups. */
+			tmigr_clean_groups(stack, start_lvl, i);
+			/* Exit after cleanup. */
+			goto out;
 		}
 
 		top = i;
@@ -1803,12 +1829,6 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node,
 	for (; i >= start_lvl; i--) {
 		group = stack[i];
 
-		if (err < 0) {
-			list_del(&group->list);
-			kfree(group);
-			continue;
-		}
-
 		WARN_ON_ONCE(i != group->level);
 
 		/*
@@ -1832,9 +1852,6 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node,
 		}
 	}
 
-	if (err < 0)
-		goto out;
-
 	if (activate) {
 		struct tmigr_walk data;
 		union tmigr_state state;
-- 
2.43.0