2022-11-12 07:47:09

by Harshit Mogalapalli

[permalink] [raw]
Subject: [PATCH] scsi: scsi_debug: Fix a warning in resp_report_zones()

As 'alloc_len' is user controlled data, 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: 7db0e0c8190a ("scsi: scsi_debug: Fix buffer size of REPORT ZONES command")
Signed-off-by: Harshit Mogalapalli <[email protected]>
---
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..eaa726654be2 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4497,7 +4497,7 @@ static int resp_report_zones(struct scsi_cmnd *scp,

rep_max_zones = (alloc_len - 64) >> ilog2(RZONES_DESC_HD);

- arr = kzalloc(alloc_len, GFP_ATOMIC);
+ arr = kzalloc(alloc_len, GFP_ATOMIC | __GFP_NOWARN);
if (!arr) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
INSUFF_RES_ASCQ);
--
2.38.1



2022-11-26 00:30:50

by Martin K. Petersen

[permalink] [raw]
Subject: Re: [PATCH] scsi: scsi_debug: Fix a warning in resp_report_zones()


Harshit,

> As 'alloc_len' is user controlled data, 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

2022-12-01 04:03:28

by Martin K. Petersen

[permalink] [raw]
Subject: Re: [PATCH] scsi: scsi_debug: Fix a warning in resp_report_zones()

On Fri, 11 Nov 2022 23:06:12 -0800, Harshit Mogalapalli wrote:

> As 'alloc_len' is user controlled data, 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_report_zones()
https://git.kernel.org/mkp/scsi/c/07f2ca139d9a

--
Martin K. Petersen Oracle Linux Engineering