[PATCH] mmc: loongson2: Fix sg iteration in data reorder functions

Binbin Zhou <[email protected]> Tue, 4 Aug 2026 14:12:00 +0800
Newsgroups org.kernel.vger.linux-mmc,org.kernel.vger.stable
Message-ID <[email protected]>
In ls2k0500_mmc_reorder_cmd_data() and ls2k2000_mmc_reorder_cmd_data(),
the for_each_sg() macro already iterates over the scatterlist entries,
with 'sg' pointing to the current entry. However, the code incorrectly
uses '&sg[i]' and 'sg_dma_len(&sg[i])' inside the loop, which treats
'sg' as an array base and indexes it again, leading to access of
wrong sg entries (or out-of-bounds if the list is not an array).

Cc: [email protected]
Fixes: d0f8e961deae ("mmc: loongson2: Add Loongson-2K2000 SD/SDIO/eMMC controller driver")
Fixes: 2115772014bd ("mmc: loongson2: Add Loongson-2K SD/SDIO controller driver")
Signed-off-by: Binbin Zhou <[email protected]>
---
 drivers/mmc/host/loongson2-mmc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/loongson2-mmc.c b/drivers/mmc/host/loongson2-mmc.c
index f553e92fd9e5..118eccbaf8cd 100644
--- a/drivers/mmc/host/loongson2-mmc.c
+++ b/drivers/mmc/host/loongson2-mmc.c
@@ -641,8 +641,8 @@ static void ls2k0500_mmc_reorder_cmd_data(struct loongson2_mmc_host *host,
 		return;
 
 	for_each_sg(cmd->data->sg, sg, cmd->data->sg_len, i) {
-		data = sg_virt(&sg[i]);
-		for (j = 0; j < (sg_dma_len(&sg[i]) / 4); j++)
+		data = sg_virt(sg);
+		for (j = 0; j < (sg_dma_len(sg) / 4); j++)
 			if (cmd->opcode == SD_SWITCH)
 				data[j] = bitrev8x4(data[j]);
 			else
@@ -758,8 +758,8 @@ static void ls2k2000_mmc_reorder_cmd_data(struct loongson2_mmc_host *host,
 		return;
 
 	for_each_sg(cmd->data->sg, sg, cmd->data->sg_len, i) {
-		data = sg_virt(&sg[i]);
-		for (j = 0; j < (sg_dma_len(&sg[i]) / 4); j++)
+		data = sg_virt(sg);
+		for (j = 0; j < (sg_dma_len(sg) / 4); j++)
 			data[j] = bitrev8x4(data[j]);
 	}
 }

base-commit: e27c946b589c53520409a0956b33d52ef7a0898f
-- 
2.52.0