net: phy: cortina: Ensure memory allocated is freed

In cs4340_upload_firmware a buffer is allocated with malloc but this is
never freed. The pointer to this buffer, addr, is not even kept
unchanged. But in some cases addr is not a buffer allocated by malloc.
Introduce the use of another pointer to keep track of the buffer and to
know if it needs to be freed.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>

diff --git a/drivers/net/phy/cortina.c b/drivers/net/phy/cortina.c
index be480ec..dec0248 100644 (file)
--- a/drivers/net/phy/cortina.c
+++ b/drivers/net/phy/cortina.c
@@ -135,6 +135,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
        int i, line_cnt = 0, column_cnt = 0;
        struct cortina_reg_config fw_temp;
        char *addr = NULL;
+       char *to_be_freed = NULL;
        ulong cortina_fw_addr = (ulong)cs4340_get_fw_addr();
 
 #ifdef CONFIG_TFABOOT
@@ -147,6 +148,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
                size_t fw_length = CONFIG_CORTINA_FW_LENGTH;
 
                addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+               to_be_freed = addr;
                ret = nand_read(get_nand_dev_by_index(0),
                                           (loff_t)cortina_fw_addr,     &fw_length, (u_char *)addr);
                if (ret == -EUCLEAN) {
@@ -158,6 +160,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
                struct spi_flash *ucode_flash;
 
                addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+               to_be_freed = addr;
                ucode_flash = spi_flash_probe(CONFIG_SF_DEFAULT_BUS, CONFIG_SF_DEFAULT_CS,
                                                                         CONFIG_SF_DEFAULT_SPEED, CONFIG_SF_DEFAULT_MODE);
                if (!ucode_flash) {
@@ -179,6 +182,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
                        puts("Failed to find MMC device for Cortina ucode\n");
                } else {
                        addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+                       to_be_freed = addr;
                        printf("MMC read: dev # %u, block # %u, count %u ...\n",
                                  dev, blk, cnt);
                        mmc_init(mmc);
@@ -199,6 +203,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
        size_t fw_length = CONFIG_CORTINA_FW_LENGTH;
 
        addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+       to_be_freed = addr;
        ret = nand_read(get_nand_dev_by_index(0),
                        (loff_t)cortina_fw_addr,
                        &fw_length, (u_char *)addr);
@@ -211,6 +216,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
        struct spi_flash *ucode_flash;
 
        addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+       to_be_freed = addr;
        ucode_flash = spi_flash_probe(CONFIG_SF_DEFAULT_BUS, CONFIG_SF_DEFAULT_CS,
                                CONFIG_SF_DEFAULT_SPEED, CONFIG_SF_DEFAULT_MODE);
        if (!ucode_flash) {
@@ -232,6 +238,7 @@ void cs4340_upload_firmware(struct phy_device *phydev)
                puts("Failed to find MMC device for Cortina ucode\n");
        } else {
                addr = malloc(CONFIG_CORTINA_FW_LENGTH);
+               to_be_freed = addr;
                printf("MMC read: dev # %u, block # %u, count %u ...\n",
                       dev, blk, cnt);
                mmc_init(mmc);
@@ -280,6 +287,8 @@ void cs4340_upload_firmware(struct phy_device *phydev)
                                     0xffff;
                phy_write(phydev, 0x00, fw_temp.reg_addr, fw_temp.reg_value);
        }
+       if (to_be_freed)
+               free(to_be_freed);
 }
 #endif