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 E22322D7DC8 for ; Thu, 21 May 2026 12:57:55 +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=1779368277; cv=none; b=DOT5hhw4Em/gPPVBWftEaa9KSkPnBbXubkK2z4W/2a+mhn6VHXOJM+hUtj/mog0OruyWIUlAHz7Xx+raJKBi+bsjVvhCF77kT4SfQp16xX++OMfj7srQzStqUtEJqri4qgw503/p71UqwW3r9oIiOvPM+WK3GSb6lMp0k9fwZJw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779368277; c=relaxed/simple; bh=mTRt4Ay6G5x1WhvAubbyL6qcd2BAEh7I3yG9LzPsWCE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gf+Wjy2JTg0QD+jY8d0gsASWW+34zYQvtc7I1HZ7ruolFrtjUhfe/BnN4M6MPj372WNnq+hcVU+wcR/XsUOtIrFey0mWyUQtS/Rmgg0kY5Uq6MLQWdi7qR/qz46CYpeebQBUza4gBQHa2EW2vzcnUcTRT5/2J2FsWEC5LgHoMLo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WWDCTwtG; 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="WWDCTwtG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E618D1F000E9; Thu, 21 May 2026 12:57:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779368275; bh=WKKnEgMM/J2o93DYjBDo0V6/Fmw4CGk7EjjMRwET7tg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WWDCTwtGpbEcU/HyEcE1+SOGlEgrKxxsUkhmGGB9kZTffr7SI0wftGG+dpJQdmS1B YGe9rUsgBVAAaGYhE843mrBUsJGn1+iB3G9wRQp6l/X+wwU98h0Gxh/253FrHgWr8d Bayu1k8ei/FeGbBgZv2u0KWxAw1J459ZO0Dwr2AsPGbXdw5R/bOV3pEYRj55NZxcFH a+wA8Z7WQdCvUoWVZd1fYPIba8ZznWUeB2oabnUi1SnjfSjSVksWXxAnwYQFGWAxo2 pQ0OcdCdLLi3oFzwpjHMsw2yypcO7C6SKvhkbDgf9icS6SVLPrBM42skCcQP8oiQS5 XxR5w4lbyz3wg== From: Sasha Levin To: stable@vger.kernel.org Cc: Samuele Mariotti , Paolo Valente , Andrea Righi , Tejun Heo , Sasha Levin Subject: [PATCH 7.0.y 1/2] sched_ext: Fix missing warning in scx_set_task_state() default case Date: Thu, 21 May 2026 08:57:52 -0400 Message-ID: <20260521125753.1164691-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026051526-prelude-boil-36f5@gregkh> References: <2026051526-prelude-boil-36f5@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: Samuele Mariotti [ Upstream commit b905ee77d5f557a83a485b4146210f54f13365fc ] In scx_set_task_state(), the default case was setting the warn flag, but then returning immediately. This is problematic because the only purpose of the warn flag is to trigger WARN_ONCE, but the early return prevented it from ever firing, leaving invalid task states undetected and untraced. To fix this, a WARN_ONCE call is now added directly in the default case. The fix addresses two aspects: - Guarantees the invalid task states are properly logged and traced. - Provides a distinct warning message ("sched_ext: Invalid task state") specifically for states outside the defined scx_task_state enum values, making it easier to distinguish from other transition warnings. This ensures proper detection and reporting of invalid states. Signed-off-by: Samuele Mariotti Signed-off-by: Paolo Valente Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo Stable-dep-of: 9a415cc53711 ("sched_ext: Avoid UAF in scx_root_enable_workfn() init failure path") Signed-off-by: Sasha Levin --- kernel/sched/ext.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 9c7ff5179e4f1..ec4a1d754d211 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -2936,7 +2936,8 @@ static void scx_set_task_state(struct task_struct *p, enum scx_task_state state) warn = prev_state != SCX_TASK_READY; break; default: - warn = true; + WARN_ONCE(1, "sched_ext: Invalid task state %d -> %d for %s[%d]", + prev_state, state, p->comm, p->pid); return; } -- 2.53.0