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

On Fri, 11 Nov 2022 23:00:31 -0800, Harshit Mogalapalli wrote:

> 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.
> 
> [...]

Applied to 6.2/scsi-queue, thanks!

[1/1] scsi: scsi_debug: Fix a warning in resp_verify()
      https://git.kernel.org/mkp/scsi/c/ed0f17b748b2

-- 
Martin K. Petersen	Oracle Linux Engineering

Harshit,

> 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.

Applied to 6.2/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering