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 0b2eaed110720b608b9208716445580c522d169e..2e69ba0143b15b2e138a1043b026e173ceba8989 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1943,6 +1943,7 @@ 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);
@@ -2012,6 +2013,7 @@ 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;
        }
 
@@ -2052,16 +2054,18 @@ 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 92a5660b88202d01d70d869aad015315eeee2104..c0d209f36188a1c229fbbe1fb583920566cc6eef 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -974,6 +974,7 @@ struct lan743x_tx {
        u32             frame_first;
        u32             frame_data0;
        u32             frame_tail;
+       u32             frame_last;
 
        struct lan743x_tx_buffer_info *buffer_info;