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 4.19-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-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bb5a3193f4adf552587010e2122f22ff2b0cd758
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 4d73a7f67dea..0733ecc9f878 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -3156,7 +3156,7 @@ 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)
