From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 579143B2FC2 for ; Thu, 18 Jun 2026 14:13:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781792025; cv=none; b=Ol47+d9TnGghte0iYX5UrZlpPKvfPjzHWm+GOgd4UQLTlKG6YgNv4jTqI+zESouoZ88/N7fP7wMS2TKautaOD82l8F5k+X3ulCSgTIzL6u0ahpmpiurdSIzJZn2wTmwZvqKt3LxO4mvsFWzrbGfYdnfc+uU0peXi+0kxmBrz2jQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781792025; c=relaxed/simple; bh=DwZgQ33ZS7bqms5nbl0ue8JaNS+VOe3nrHPr9k+PPVo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tgnoaE2UJrfnv8B6OePJrFjlF9M8Y7k+nqv+mKVX8piuk4hapYvyyc4/05k7tl3VeoSUKP6joW+jfgtFRGdLRtt/hk0D8bOtrKHirkLJVNpvcxH+CAm1wrdLZ/blSoYDnIboFTw0mo4aOcR6XJUduqkVvO07wohJavGLjl8nIUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IvSWdDCv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IvSWdDCv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7941B1F000E9; Thu, 18 Jun 2026 14:13:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781792024; bh=aehrTraPV6Mblmer2c6D81tWkH6Ag1jZINaxqlPSDEo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IvSWdDCvgObqFrSP1DKVA87o6VKg4Jdy7+Nr1RDt0oyNt4Cgaq1B7vO9Lkh3x8Jc4 mWrYJeEielajx/Q5UIomUrukP5UQNSFslFrd5yc8A60K4cJcKMUTgYFkJXm9Gcibxx Ev3JJ5CvRcZI7TqwplPV98cXhkS+HH7zl4Ovjwk+8Yioiz/ALdb1Ui3x91yAL0ndl7 gpja+bR+gNILln145O+V340tQDCVNpFweTfOJa/DWCAbGfotj3S8grRnN5g3INGO+L pHjwliCAgWpwV8lgQubP/i3sbWjab5tGUdeRyiao5bhXQoDMXcsMHGp8fWnvG7sH/G 8ZgboPHlmxqZg== From: Sasha Levin To: stable@vger.kernel.org Cc: Helen Koike , syzbot+b8ca586b9fc235f0c0df@syzkaller.appspotmail.com, Thomas Gleixner , Sasha Levin Subject: [PATCH 6.1.y] debugobjects: Do not fill_pool() if pi_blocked_on Date: Thu, 18 Jun 2026 10:13:40 -0400 Message-ID: <20260618141340.734280-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026061611-defective-unbundle-fbc8@gregkh> References: <2026061611-defective-unbundle-fbc8@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Helen Koike [ Upstream commit 5f41161059fd0f1bbf18c90f3180e38cc45a14eb ] On RT enabled kernels, fill_pool() ends up calling rtlock_lock(), which asserts if current::pi_blocked_on is set, because a task can obviously only block on one lock as otherwise the priority inheritenace chain gets corrupted. Prevent this by expanding the conditional to take current::pi_blocked_on into account. Fixes: 4bedcc28469a ("debugobjects: Make them PREEMPT_RT aware") Reported-by: syzbot+b8ca586b9fc235f0c0df@syzkaller.appspotmail.com Signed-off-by: Helen Koike Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/20260511215359.3351259-1-koike@igalia.com Closes: https://syzkaller.appspot.com/bug?extid=b8ca586b9fc235f0c0df Signed-off-by: Sasha Levin --- lib/debugobjects.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 8c3b483a8fb44a..f9d53a0af4238f 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -597,13 +597,23 @@ static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket return NULL; } +static inline bool debug_objects_is_pi_blocked_on(void) +{ +#ifdef CONFIG_RT_MUTEXES + return current->pi_blocked_on != NULL; +#else + return false; +#endif +} + static void debug_objects_fill_pool(void) { /* * On RT enabled kernels the pool refill must happen in preemptible - * context: + * context and not enqueued on an rt_mutex: */ - if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) + if (!IS_ENABLED(CONFIG_PREEMPT_RT) || + (preemptible() && !debug_objects_is_pi_blocked_on())) fill_pool(); } -- 2.53.0