linux-kernel - [PATCH] debug: Fix a NULL vs IS_ERR() bug in __debug_object

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>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251110075746.1680-1-vulab@iscas.ac.cn>
Date: Mon, 10 Nov 2025 15:57:46 +0800
From: Haotian Zhang <vulab@...as.ac.cn>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>
Cc: linux-kernel@...r.kernel.org,
	Haotian Zhang <vulab@...as.ac.cn>
Subject: [PATCH] debug: Fix a NULL vs IS_ERR() bug in __debug_object_init()

The lookup_object_or_alloc() returns error pointers on failure, but the
code only checks for NULL. This leads to dereferencing an invalid error
pointer and causes a kernel crash.

Use IS_ERR_OR_NULL() instead of a NULL check to properly handle both
error pointers and NULL returns.

Fixes: 63a759694eed ("debugobject: Prevent init race with static objects")
Signed-off-by: Haotian Zhang <vulab@...as.ac.cn>
---
 lib/debugobjects.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 7f50c4480a4e..9587ef619054 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -741,9 +741,10 @@ __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack
 	raw_spin_lock_irqsave(&db->lock, flags);
 
 	obj = lookup_object_or_alloc(addr, db, descr, onstack, false);
-	if (unlikely(!obj)) {
+	if (IS_ERR_OR_NULL(obj)) {
 		raw_spin_unlock_irqrestore(&db->lock, flags);
-		debug_objects_oom();
+		if (!obj)
+			debug_objects_oom();
 		return;
 	}
 
-- 
2.50.1.windows.1