This is a note to let you know that I've just added the patch titled scsi: scsi_debug: Fix a warning in resp_write_scat() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-scsi_debug-fix-a-warning-in-resp_write_scat.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f76d491463a8de6e4a543a0d0325a5fffe5b18f7 Author: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx> Date: Fri Nov 11 02:05:25 2022 -0800 scsi: scsi_debug: Fix a warning in resp_write_scat() [ 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@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221111100526.1790533-1-harshit.m.mogalapalli@xxxxxxxxxx Acked-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index 0b16061d8da8..b44fd9b80934 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -3640,7 +3640,7 @@ 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)