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

From: Everest K.C.
Date: Tue Oct 15 2024 - 17:53:21 EST


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@xxxxxxxxxxxxxxxx>
---
drivers/staging/gpib/ni_usb/ni_usb_gpib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
index 1da263676f2a..75f39e1f3ed1 100644
--- 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;
--
2.43.0