From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2F9EA314B71 for ; Mon, 3 Nov 2025 15:06:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762182392; cv=none; b=JDVi4FsXrzo6Bo9q03Vkrd5eds3Fq/zxRDjHf3KK3RERM9BsdLaXQp6YX/oyAHNqkUEDEnMw+PGDB1r/cy4McljKajnCs4k1b06SgQl8pD1ElR6KGdEPEkM6niUw5IVLm/zl06XF26WW/qtjAA2L6xvBEKtfTOSZyu9mqFblbnA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762182392; c=relaxed/simple; bh=Xe8cPSqrgDHXwOZig0tkU1vtczIZ1flq2cHyMveTtuY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pE24UgEIc2N00Z8ksiMNoerZriCynIzeBcT+WgWU2et6WWasMqyQto+g0sKAtdYZ5SQ3KO6kpPJdZdJdToV80I4TyBHCVbux0ONF+jrC6dxRRBDwe2CSuQMrQrIRiIbElz2/qWucb9ycVcWMH9Aa92p58GjdhCtzHPMkA+0/4zU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gKNKVwNb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gKNKVwNb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B281C4CEE7; Mon, 3 Nov 2025 15:06:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762182391; bh=Xe8cPSqrgDHXwOZig0tkU1vtczIZ1flq2cHyMveTtuY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gKNKVwNbPwgpNLgv7gk6m3h9qKG6SEszGzI5JFOR2AEFCOFhSDlZMDfWj4Z8HvKcp JftflzJUN5cJTKnKBDLaRwhZCue3gNoN0a32av14aS6jFFjt9wWUuXQ/xDu7Sc8IxA 7bUU23VUmeJDiOGYSpamJp3hvS79tBzuaCeHby39OnodSlAxWj+t76B0ldU3c7CR+/ 0xCYQjs6vFm+VZsq3o+FTjxvFrMB+RhjfF1uBBVpLvDpQx4DuEUgLKMsbXi6uhu40o Da/U1j2/hj+MGKLgU6T8aqvJd39VGLhqGVPYGx73klq3vmv1Zei8zIIJEgse5462vD q3rbJWuAsvMqg== From: Sasha Levin To: stable@vger.kernel.org Cc: Philipp Stanner , Tvrtko Ursulin , Sasha Levin Subject: [PATCH 6.1.y] drm/sched: Fix race in drm_sched_entity_select_rq() Date: Mon, 3 Nov 2025 10:06:29 -0500 Message-ID: <20251103150629.4044990-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025110343-daffodil-target-5d2b@gregkh> References: <2025110343-daffodil-target-5d2b@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: Philipp Stanner [ Upstream commit d25e3a610bae03bffc5c14b5d944a5d0cd844678 ] In a past bug fix it was forgotten that entity access must be protected by the entity lock. That's a data race and potentially UB. Move the spin_unlock() to the appropriate position. Cc: stable@vger.kernel.org # v5.13+ Fixes: ac4eb83ab255 ("drm/sched: select new rq even if there is only one v3") Reviewed-by: Tvrtko Ursulin Signed-off-by: Philipp Stanner Link: https://patch.msgid.link/20251022063402.87318-2-phasta@kernel.org [ adapted lock field name from entity->lock to entity->rq_lock ] Signed-off-by: Sasha Levin --- drivers/gpu/drm/scheduler/sched_entity.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 2634a555d2758..3f68a47e34062 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -471,10 +471,11 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity) drm_sched_rq_remove_entity(entity->rq, entity); entity->rq = rq; } - spin_unlock(&entity->rq_lock); if (entity->num_sched_list == 1) entity->sched_list = NULL; + + spin_unlock(&entity->rq_lock); } /** -- 2.51.0