[PATCH] scsi: aacraid: Fix DMA mapping leak in aac_send_raw_srb error paths

[Yuhao Jiang <danisjiang@gmail.com>]

The aac_send_raw_srb function creates DMA mappings for scatter-gather
buffers but fails to unmap them in most error paths, leading to DMA
mapping resource leaks.

This patch fixes all error paths except -ERESTARTSYS. The -ERESTARTSYS
case is a known design issue where resources cannot be safely freed
(hardware may still be accessing them) but also cannot be properly
tracked for later cleanup (they are local variables).

Fixed paths:
- copy_from_user failures during SG buffer setup
- aac_hba_send/aac_fib_send errors after DMA mapping
- copy_to_user failures after successful command execution

Fixes: 423400e64d377 ("scsi: aacraid: Include HBA direct interface")
Cc: stable@vger.kernel.org
Signed-off-by: Yuhao Jiang <danisjiang@gmail.com>
---
 drivers/scsi/aacraid/commctrl.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
index 68240d6f27ab..e0495f278e2e 100644
--- a/drivers/scsi/aacraid/commctrl.c
+++ b/drivers/scsi/aacraid/commctrl.c
@@ -493,6 +493,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 	void __user *sg_user[HBA_MAX_SG_EMBEDDED];
 	void *sg_list[HBA_MAX_SG_EMBEDDED];
 	u32 sg_count[HBA_MAX_SG_EMBEDDED];
+	dma_addr_t sg_dma_addr[HBA_MAX_SG_EMBEDDED];
+	int sg_dma_last_mapped = -1;
 	u32 sg_indx = 0;
 	u32 byte_count = 0;
 	u32 actual_fibsize64, actual_fibsize = 0;
@@ -690,6 +692,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 			}
 			addr = dma_map_single(&dev->pdev->dev, p, sg_count[i],
 					      data_dir);
+			sg_dma_addr[i] = addr;
+			sg_dma_last_mapped = i;
 			hbacmd->sge[i].addr_hi = cpu_to_le32((u32)(addr>>32));
 			hbacmd->sge[i].addr_lo = cpu_to_le32(
 						(u32)(addr & 0xffffffff));
@@ -752,6 +756,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 				}
 				addr = dma_map_single(&dev->pdev->dev, p,
 						      sg_count[i], data_dir);
+				sg_dma_addr[i] = addr;
+				sg_dma_last_mapped = i;
 
 				psg->sg[i].addr[0] = cpu_to_le32(addr & 0xffffffff);
 				psg->sg[i].addr[1] = cpu_to_le32(addr>>32);
@@ -808,6 +814,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 				}
 				addr = dma_map_single(&dev->pdev->dev, p,
 						      sg_count[i], data_dir);
+				sg_dma_addr[i] = addr;
+				sg_dma_last_mapped = i;
 
 				psg->sg[i].addr[0] = cpu_to_le32(addr & 0xffffffff);
 				psg->sg[i].addr[1] = cpu_to_le32(addr>>32);
@@ -865,6 +873,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 				addr = dma_map_single(&dev->pdev->dev, p,
 						      usg->sg[i].count,
 						      data_dir);
+				sg_dma_addr[i] = addr;
+				sg_dma_last_mapped = i;
 
 				psg->sg[i].addr = cpu_to_le32(addr & 0xffffffff);
 				byte_count += usg->sg[i].count;
@@ -905,6 +915,8 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 				}
 				addr = dma_map_single(&dev->pdev->dev, p,
 						      sg_count[i], data_dir);
+				sg_dma_addr[i] = addr;
+				sg_dma_last_mapped = i;
 
 				psg->sg[i].addr = cpu_to_le32(addr);
 				byte_count += sg_count[i];
@@ -986,6 +998,10 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
 cleanup:
 	kfree(user_srbcmd);
 	if (rcode != -ERESTARTSYS) {
+		for (i = 0; i <= sg_dma_last_mapped; i++) {
+			dma_unmap_single(&dev->pdev->dev, sg_dma_addr[i],
+					 sg_count[i], data_dir);
+		}
 		for (i = 0; i <= sg_indx; i++)
 			kfree(sg_list[i]);
 		aac_fib_complete(srbfib);
-- 
2.34.1