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 DBA201C860D; Wed, 5 Mar 2025 18:05:42 +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=1741197943; cv=none; b=ntHMabe4xo/CdNeQk8P9pqsfNuezQb32mETQrl6bO5IsYIjdiBmo4z4Bp8U3/8fE/OMJqosaXi376WYGLYOvJIX6DDaCqQBeII4LPyqSLodr+grVtWc4AgD0iwtiVBbogHPCgn3YlQCu0bI1S4sL2RwQrT9hMeXmYDuSgyjJaNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741197943; c=relaxed/simple; bh=Qu1b39enMVBcjAuqU+BXY14c8GzTUuh0rF2qx8v/pvc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r2K0aAunWYpfxJmTrOikHD9uepz+HZbN0OLN52hB91Zz3Ofbx9SH4HWi0j8dalrcWyQAq/YvGBm5Yp5qR2knDf1d11zlOE+DOSEgVt3eLHErJad+mS2GlY7+FeLGILTxd+o2jFfPl+/EIY2YdeYBTfriTQ+qt8+XkbvjMNGSjA8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FLALPwAz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FLALPwAz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 646EBC4CED1; Wed, 5 Mar 2025 18:05:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741197942; bh=Qu1b39enMVBcjAuqU+BXY14c8GzTUuh0rF2qx8v/pvc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FLALPwAzkjsZK1MFCfBfrGuvhjnyev11M7rkcZ4dl0/ZqXPA5HxaDkriAgxpazAFp nshsPdBA5zz0NFQk6EGexi1IKnWVdZGcvHHf45PTZuizZGI7blY0ESoxUpF6lIAK5w U5mO/0H9AJh6WZp5neHL9ugA1zinnehKaSm4GFQU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yishai Hadas , Artemy Kovalyov , Leon Romanovsky , Sasha Levin Subject: [PATCH 6.12 003/150] RDMA/mlx5: Fix a race for DMABUF MR which can lead to CQE with error Date: Wed, 5 Mar 2025 18:47:12 +0100 Message-ID: <20250305174503.942620589@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250305174503.801402104@linuxfoundation.org> References: <20250305174503.801402104@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yishai Hadas [ Upstream commit cc668a11e6ac8adb0e016711080d3f314722cc91 ] This patch addresses a potential race condition for a DMABUF MR that can result in a CQE with an error on the UMR QP. During the __mlx5_ib_dereg_mr() flow, the following sequence of calls occurs: mlx5_revoke_mr() mlx5r_umr_revoke_mr() mlx5r_umr_post_send_wait() At this point, the lkey is freed from the hardware's perspective. However, concurrently, mlx5_ib_dmabuf_invalidate_cb() might be triggered by another task attempting to invalidate the MR having that freed lkey. Since the lkey has already been freed, this can lead to a CQE error, causing the UMR QP to enter an error state. To resolve this race condition, the dma_resv_lock() which was hold as part of the mlx5_ib_dmabuf_invalidate_cb() is now also acquired as part of the mlx5_revoke_mr() scope. Upon a successful revoke, we set umem_dmabuf->private which points to that MR to NULL, preventing any further invalidation attempts on its lkey. Fixes: e6fb246ccafb ("RDMA/mlx5: Consolidate MR destruction to mlx5_ib_dereg_mr()") Signed-off-by: Yishai Hadas Reviewed-by: Artemy Kovalyov Link: https://patch.msgid.link/70617067abbfaa0c816a2544c922e7f4346def58.1738587016.git.leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/hw/mlx5/mr.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index bb02b6adbf2c2..0a3cbb14e1839 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1550,7 +1550,7 @@ static void mlx5_ib_dmabuf_invalidate_cb(struct dma_buf_attachment *attach) dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv); - if (!umem_dmabuf->sgt) + if (!umem_dmabuf->sgt || !mr) return; mlx5r_umr_update_mr_pas(mr, MLX5_IB_UPD_XLT_ZAP); @@ -2022,11 +2022,16 @@ static int mlx5_revoke_mr(struct mlx5_ib_mr *mr) struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.device); struct mlx5_cache_ent *ent = mr->mmkey.cache_ent; bool is_odp = is_odp_mr(mr); + bool is_odp_dma_buf = is_dmabuf_mr(mr) && + !to_ib_umem_dmabuf(mr->umem)->pinned; int ret = 0; if (is_odp) mutex_lock(&to_ib_umem_odp(mr->umem)->umem_mutex); + if (is_odp_dma_buf) + dma_resv_lock(to_ib_umem_dmabuf(mr->umem)->attach->dmabuf->resv, NULL); + if (mr->mmkey.cacheable && !mlx5r_umr_revoke_mr(mr) && !cache_ent_find_and_store(dev, mr)) { ent = mr->mmkey.cache_ent; /* upon storing to a clean temp entry - schedule its cleanup */ @@ -2054,6 +2059,12 @@ static int mlx5_revoke_mr(struct mlx5_ib_mr *mr) mutex_unlock(&to_ib_umem_odp(mr->umem)->umem_mutex); } + if (is_odp_dma_buf) { + if (!ret) + to_ib_umem_dmabuf(mr->umem)->private = NULL; + dma_resv_unlock(to_ib_umem_dmabuf(mr->umem)->attach->dmabuf->resv); + } + return ret; } -- 2.39.5