[PATCH 6.18 243/250] scsi: scsi_debug: Negate wrapped memcmp() result

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Xu Rao <raoxu@uniontech.com>

commit c4f6916a99cf105c3ff340b6210fcbba3fa66b35 upstream.

comp_write_worker() returns true when the compared data matches.
memcmp() returns zero for equal data and non-zero for different data, so
its result must be negated before it is stored in a bool.

The first segment already uses !memcmp(), but the wrapped segment uses
memcmp() directly, reversing the match result. Use !memcmp() there as
well.

Fixes: 38d5c8336e60 ("scsi_debug: add Report supported opcodes+tmfs; Compare and write")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://patch.msgid.link/E5AD42E9C0E18633+20260803095328.3445311-1-raoxu@uniontech.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/scsi/scsi_debug.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4322,8 +4322,8 @@ static bool comp_write_worker(struct sde
 	if (!res)
 		return res;
 	if (rest)
-		res = memcmp(fsp, arr + ((num - rest) * lb_size),
-			     rest * lb_size);
+		res = !memcmp(fsp, arr + ((num - rest) * lb_size),
+			      rest * lb_size);
 	if (!res)
 		return res;
 	if (compare_only)