[PATCH] scsi: scsi_debug: Fix a warning in resp_verify()

From: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
To: unlisted-recipients:; (no To-header on input)
Cc: harshit.m.mogalapalli@oracle.com, error27@gmail.com,
	harshit.m.mogalapalli@gmail.com,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Hannes Reinecke <hare@suse.de>,
	Douglas Gilbert <dgilbert@interlog.com>,
	linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] scsi: scsi_debug: Fix a warning in resp_verify()
Date: Fri, 11 Nov 2022 23:00:31 -0800	[thread overview]
Message-ID: <20221112070031.2121068-1-harshit.m.mogalapalli@oracle.com> (raw)

As 'vnum' is controlled by user, so if user tries to allocate memory
larger than(>=) MAX_ORDER, then kcalloc() will fail, it creates a stack
trace and messes up dmesg with a warning.

Add __GFP_NOWARN in order to avoid too large allocation warning.
This is detected by static analysis using smatch.

Fixes: c3e2fe9222d4 ("scsi: scsi_debug: Implement VERIFY(10), add VERIFY(16)")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
---
 drivers/scsi/scsi_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 697fc57bc711..cbb9395c90c1 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4429,7 +4429,7 @@ static int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 	if (ret)
 		return ret;
 
-	arr = kcalloc(lb_size, vnum, GFP_ATOMIC);
+	arr = kcalloc(lb_size, vnum, GFP_ATOMIC | __GFP_NOWARN);
 	if (!arr) {
 		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
 				INSUFF_RES_ASCQ);
-- 
2.38.1

