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Tue, 16 Jun 2026 10:31:57 +0800 From: Hongling Zeng To: vkoul@kernel.org, Frank.Li@kernel.org, wens@kernel.org, jernej.skrabec@gmail.com, samuel@sholland.org, mripard@kernel.org, arnd@arndb.de Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, zhongling0719@126.com, Hongling Zeng Subject: [PATCH v3] dmaengine: sun6i-dma: Fix use-after-free in error handling paths Date: Tue, 16 Jun 2026 10:31:38 +0800 Message-Id: <20260616023138.15904-1-zenghongling@kylinos.cn> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Server: rspamd-worker-8404 X-Spamd-Result: default: False [-0.66 / 15.00]; BAYES_HAM(-5.50)[100.00%]; RBL_SENDERSCORE(2.00)[172.234.253.10:from]; SUSPICIOUS_RECIPS(1.50)[]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; MAILLIST(-0.15)[generic]; BAD_REP_POLICIES(0.10)[]; MIME_GOOD(-0.10)[text/plain]; 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Fix by saving both the next virtual and physical pointers before freeing the current node. Fixes: 555859308723 ("dmaengine: Add driver for Allwinner sun6i DMA") Signed-off-by: Hongling Zeng Suggested-by: Jernej Skrabec Reviewed-by: Jernej Skrabec --- Changes in v2: -Refactored the fix to avoid code duplication by creating a helper function sun6i_dma_free_lli_list() that handles LLI list cleanup -Add Suggested-by: Jernej Skrabec --- Change in v3: -Further refactoring to move txd handling into the helper function as suggested by Jernej --- drivers/dma/sun6i-dma.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index a9a254dbf8cb..7a79f346250a 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -406,16 +406,12 @@ static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan, v_lli->len, v_lli->para, v_lli->p_lli_next); } -static void sun6i_dma_free_desc(struct virt_dma_desc *vd) +static void sun6i_dma_free_desc(struct sun6i_dma_dev *sdev, + struct sun6i_desc *txd) { - struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); - struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device); struct sun6i_dma_lli *v_lli, *v_next; dma_addr_t p_lli, p_next; - if (unlikely(!txd)) - return; - p_lli = txd->p_lli; v_lli = txd->v_lli; @@ -432,6 +428,17 @@ static void sun6i_dma_free_desc(struct virt_dma_desc *vd) kfree(txd); } +static void sun6i_dma_free_desc_virt(struct virt_dma_desc *vd) +{ + struct sun6i_desc *txd = to_sun6i_desc(&vd->tx); + struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device); + + if (unlikely(!txd)) + return; + + sun6i_dma_free_desc(sdev, txd); +} + static int sun6i_dma_start_desc(struct sun6i_vchan *vchan) { struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device); @@ -788,10 +795,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg( return vchan_tx_prep(&vchan->vc, &txd->vd, flags); err_lli_free: - for (p_lli = txd->p_lli, v_lli = txd->v_lli; v_lli; - p_lli = v_lli->p_lli_next, v_lli = v_lli->v_lli_next) - dma_pool_free(sdev->pool, v_lli, p_lli); - kfree(txd); + sun6i_dma_free_desc(sdev, txd); return NULL; } @@ -869,10 +873,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_cyclic( return vchan_tx_prep(&vchan->vc, &txd->vd, flags); err_lli_free: - for (p_lli = txd->p_lli, v_lli = txd->v_lli; v_lli; - p_lli = v_lli->p_lli_next, v_lli = v_lli->v_lli_next) - dma_pool_free(sdev->pool, v_lli, p_lli); - kfree(txd); + sun6i_dma_free_desc(sdev, txd); return NULL; } @@ -1431,7 +1432,7 @@ static int sun6i_dma_probe(struct platform_device *pdev) struct sun6i_vchan *vchan = &sdc->vchans[i]; INIT_LIST_HEAD(&vchan->node); - vchan->vc.desc_free = sun6i_dma_free_desc; + vchan->vc.desc_free = sun6i_dma_free_desc_virt; vchan_init(&vchan->vc, &sdc->slave); }