From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AF5CC678D4 for ; Tue, 7 Mar 2023 17:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231996AbjCGRjW (ORCPT ); Tue, 7 Mar 2023 12:39:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231998AbjCGRi4 (ORCPT ); Tue, 7 Mar 2023 12:38:56 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74A879CFDE for ; Tue, 7 Mar 2023 09:35:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 12669B81851 for ; Tue, 7 Mar 2023 17:35:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79360C433D2; Tue, 7 Mar 2023 17:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210510; bh=7fymXT6a76Kfg39zLL2wxjZ6QOHP06Z+W0Vp4ZfdjD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nw0+cG3MvfQ/aqyDxXtdHjSy0EuvVz4vfugCGkwkV/VjWxiTdnfMPfAtoLifCRZXx L6+Rv3cYsux6BFZImeIwihXfhXCmOPHqrqUqeyPZiDugt3/bgqFElubDpy0IfvhEi9 QHGZiVn+n61wuXLIn2mNNcb7S6NqFUdY/Lq1LLD4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shravan Chippa , Conor Dooley , Vinod Koul , Sasha Levin Subject: [PATCH 6.2 0565/1001] dmaengine: sf-pdma: pdma_desc memory leak fix Date: Tue, 7 Mar 2023 17:55:37 +0100 Message-Id: <20230307170045.997667637@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shravan Chippa [ Upstream commit b02e07015a5ac7bbc029da931ae17914b8ae0339 ] Commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel") changed sf_pdma_prep_dma_memcpy() to unconditionally allocate a new sf_pdma_desc each time it is called. The driver previously recycled descs, by checking the in_use flag, only allocating additional descs if the existing one was in use. This logic was removed in commit b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel"), but sf_pdma_free_desc() was not changed to handle the new behaviour. As a result, each time sf_pdma_prep_dma_memcpy() is called, the previous descriptor is leaked, over time leading to memory starvation: unreferenced object 0xffffffe008447300 (size 192): comm "irq/39-mchp_dsc", pid 343, jiffies 4294906910 (age 981.200s) hex dump (first 32 bytes): 00 00 00 ff 00 00 00 00 b8 c1 00 00 00 00 00 00 ................ 00 00 70 08 10 00 00 00 00 00 00 c0 00 00 00 00 ..p............. backtrace: [<00000000064a04f4>] kmemleak_alloc+0x1e/0x28 [<00000000018927a7>] kmem_cache_alloc+0x11e/0x178 [<000000002aea8d16>] sf_pdma_prep_dma_memcpy+0x40/0x112 Add the missing kfree() to sf_pdma_free_desc(), and remove the redundant in_use flag. Fixes: b2cc5c465c2c ("dmaengine: sf-pdma: Add multithread support for a DMA channel") Signed-off-by: Shravan Chippa Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230120100623.3530634-1-shravan.chippa@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/sf-pdma/sf-pdma.c | 3 +-- drivers/dma/sf-pdma/sf-pdma.h | 1 - 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c index 6b524eb6bcf3a..e578ad5569494 100644 --- a/drivers/dma/sf-pdma/sf-pdma.c +++ b/drivers/dma/sf-pdma/sf-pdma.c @@ -96,7 +96,6 @@ sf_pdma_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dest, dma_addr_t src, if (!desc) return NULL; - desc->in_use = true; desc->dirn = DMA_MEM_TO_MEM; desc->async_tx = vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); @@ -290,7 +289,7 @@ static void sf_pdma_free_desc(struct virt_dma_desc *vdesc) struct sf_pdma_desc *desc; desc = to_sf_pdma_desc(vdesc); - desc->in_use = false; + kfree(desc); } static void sf_pdma_donebh_tasklet(struct tasklet_struct *t) diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h index dcb3687bd5da2..5c398a83b491a 100644 --- a/drivers/dma/sf-pdma/sf-pdma.h +++ b/drivers/dma/sf-pdma/sf-pdma.h @@ -78,7 +78,6 @@ struct sf_pdma_desc { u64 src_addr; struct virt_dma_desc vdesc; struct sf_pdma_chan *chan; - bool in_use; enum dma_transfer_direction dirn; struct dma_async_tx_descriptor *async_tx; }; -- 2.39.2