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 a3392c74372a864baea96a88e3791417f4675938..fe919c1974505c1d73b680af016a735f44d62d2a 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -1448,6 +1448,7 @@ 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);
@@ -1517,6 +1518,7 @@ 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;
        }
 
@@ -1557,16 +1559,18 @@ 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 6080028c1df2c7946d15d9854432b1444ae8be29..a1226ab0fb42171114a1dc56bc5fb18cc0f5a990 100644 (file)
--- a/drivers/net/ethernet/microchip/lan743x_main.h
+++ b/drivers/net/ethernet/microchip/lan743x_main.h
@@ -658,6 +658,7 @@ struct lan743x_tx {
        u32             frame_first;
        u32             frame_data0;
        u32             frame_tail;
+       u32             frame_last;
 
        struct lan743x_tx_buffer_info *buffer_info;