staging: gpib: Move free after the variable use has been completed

The variable `in_data` is freed, but used later in the code.
Fix it by moving the freeing the memory after it use has been
completed.

This issue was reported by Coverity Scan.
Report:
CID 1600783: (#1 of 1): Use after free (USE_AFTER_FREE)
19. pass_freed_arg: Passing freed pointer in_data as an argument to
ni_usb_dump_raw_block.

Fixes: 4e127de14fa7 ("staging: gpib: Add National Instruments USB GPIB driver")
Signed-off-by: Everest K.C. <everestkc@everestkc.com.np>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241015215157.18571-1-everestkc@everestkc.com.np
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
index 1da263676f2a35d39ebb1c3aa3b7a6db780fdfb8..75f39e1f3ed1f7d47593f485102b44c5b4027719 100644 (file)
--- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
+++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
@@ -690,12 +690,12 @@ static int ni_usb_read(gpib_board_t *board, uint8_t *buffer, size_t length,
                kfree(in_data);
                return parse_retval;
        }
-       kfree(in_data);
        if (actual_length != length - status.count) {
                pr_err("%s: actual_length=%i expected=%li\n",
                       __func__, actual_length, (long)(length - status.count));
                ni_usb_dump_raw_block(in_data, usb_bytes_read);
        }
+       kfree(in_data);
        switch (status.error_code) {
        case NIUSB_NO_ERROR:
                retval = 0;