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 9028ABA48 for ; Tue, 7 Mar 2023 18:22:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7961C433D2; Tue, 7 Mar 2023 18:22:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678213362; bh=7fymXT6a76Kfg39zLL2wxjZ6QOHP06Z+W0Vp4ZfdjD0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GAsXK7+7StEH3hcc6xsYtvhJqqAbNbO5acR4GEQK5qQGPvw0fxbCX85aKMcX4mNIH GG/rlQuXpYLYb2OCBGX7fcDk2GxniLYzoePAcARWZ61lS3MjD7U51R3W3UWTzvfELB 8jk5K38wNLyPIN7JGIWLRTE6zSiahkuuO5Sa0Ds8= 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 6.1 484/885] dmaengine: sf-pdma: pdma_desc memory leak fix Date: Tue, 7 Mar 2023 17:56:58 +0100 Message-Id: <20230307170023.495513962@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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