From: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com
[ Upstream commit 216e179724c1d9f57a8ababf8bd7aaabef67f01b ]
As 'lbdof_blen' is coming from user, if the size in kzalloc() is >= MAX_ORDER then we hit a warning.
Call trace:
sg_ioctl sg_ioctl_common scsi_ioctl sg_scsi_ioctl blk_execute_rq blk_mq_sched_insert_request blk_mq_run_hw_queue __blk_mq_delay_run_hw_queue __blk_mq_run_hw_queue blk_mq_sched_dispatch_requests __blk_mq_sched_dispatch_requests blk_mq_dispatch_rq_list scsi_queue_rq scsi_dispatch_cmd scsi_debug_queuecommand schedule_resp resp_write_scat
If you try to allocate a memory larger than(>=) MAX_ORDER, then kmalloc() will definitely fail. It creates a stack trace and messes up dmesg. The user controls the size here so if they specify a too large size it will fail.
Add __GFP_NOWARN in order to avoid too large allocation warning. This is detected by static analysis using smatch.
Fixes: 481b5e5c7949 ("scsi: scsi_debug: add resp_write_scat function") Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com Link: https://lore.kernel.org/r/20221111100526.1790533-1-harshit.m.mogalapalli@ora... Acked-by: Douglas Gilbert dgilbert@interlog.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 408166bd20f3..2c86ed1dc4b5 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -3139,7 +3139,7 @@ static int resp_write_scat(struct scsi_cmnd *scp, mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0); return illegal_condition_result; } - lrdp = kzalloc(lbdof_blen, GFP_ATOMIC); + lrdp = kzalloc(lbdof_blen, GFP_ATOMIC | __GFP_NOWARN); if (lrdp == NULL) return SCSI_MLQUEUE_HOST_BUSY; if (sdebug_verbose)