net: lan743x: Fix memleak issue when GSO enabled

[ Upstream commit 2d52e2e38b85c8b7bc00dca55c2499f46f8c8198 ]

Always map the `skb` to the LS descriptor. Previously skb was
mapped to EXT descriptor when the number of fragments is zero with
GSO enabled. Mapping the skb to EXT descriptor prevents it from
being freed, leading to a memory leak

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Thangaraj Samynathan <thangaraj.s@microchip.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20250429052527.10031-1-thangaraj.s@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 50cb1c5251f71071c5e9e2cd8f5e2f262030fd4f..a0f490a907573b3c2d7c8510758287109568a454 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1475,6 +1475,7 @@ static void lan743x_tx_frame_add_lso(struct lan743x_tx *tx,
        if (nr_frags <= 0) {
                tx->frame_data0 |= TX_DESC_DATA0_LS_;
                tx->frame_data0 |= TX_DESC_DATA0_IOC_;
+               tx->frame_last = tx->frame_first;
        }
        tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
        tx_descriptor->data0 = cpu_to_le32(tx->frame_data0);
@@ -1544,6 +1545,7 @@ static int lan743x_tx_frame_add_fragment(struct lan743x_tx *tx,
                tx->frame_first = 0;
                tx->frame_data0 = 0;
                tx->frame_tail = 0;
+               tx->frame_last = 0;
                return -ENOMEM;
        }
 
@@ -1584,16 +1586,18 @@ static void lan743x_tx_frame_end(struct lan743x_tx *tx,
            TX_DESC_DATA0_DTYPE_DATA_) {
                tx->frame_data0 |= TX_DESC_DATA0_LS_;
                tx->frame_data0 |= TX_DESC_DATA0_IOC_;
+               tx->frame_last = tx->frame_tail;
        }
 
-       tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
-       buffer_info = &tx->buffer_info[tx->frame_tail];
+       tx_descriptor = &tx->ring_cpu_ptr[tx->frame_last];
+       buffer_info = &tx->buffer_info[tx->frame_last];
        buffer_info->skb = skb;
        if (time_stamp)
                buffer_info->flags |= TX_BUFFER_INFO_FLAG_TIMESTAMP_REQUESTED;
        if (ignore_sync)
                buffer_info->flags |= TX_BUFFER_INFO_FLAG_IGNORE_SYNC;
 
+       tx_descriptor = &tx->ring_cpu_ptr[tx->frame_tail];
        tx_descriptor->data0 = cpu_to_le32(tx->frame_data0);
        tx->frame_tail = lan743x_tx_next_index(tx, tx->frame_tail);
        tx->last_tail = tx->frame_tail;

diff --git a/drivers/net/ethernet/microchip/lan743x_main.h b/drivers/net/ethernet/microchip/lan743x_main.h
index 751f2bc9ce84ecfacab33659c98e981b0b8bf32e..2a40cc827b1872aacde8bd9b659a49cba0683687 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -657,6 +657,7 @@ struct lan743x_tx {
        u32             frame_first;
        u32             frame_data0;
        u32             frame_tail;
+       u32             frame_last;
 
        struct lan743x_tx_buffer_info *buffer_info;