On 2018-06-18 12:08 PM, Luis Henriques wrote:

Since commit 80c49563e250 ("scsi: scsi_debug: implement IMMED bit") there are long delays in F_SYNC_DELAY and F_SSU_DELAY. This can cause a memory leak in schedule_resp(), which can be invoked while unloading the scsi_debug module: free_all_queued() had already freed all sd_dp and schedule_resp will alloc a new one, which will never get freed. Here's the kmemleak report while running xfstests generic/350:

unreferenced object 0xffff88007d752b00 (size 128): comm "rmmod", pid 26940, jiffies 4295816945 (age 7.588s) hex dump (first 32 bytes): 00 2b 75 7d 00 88 ff ff 00 00 00 00 00 00 00 00 .+u}............ 00 00 00 00 00 00 00 00 8e 31 a2 34 5f 03 00 00 .........1.4_... backtrace: [<000000002abd83d0>] 0xffffffffa000705e [<000000004c063fda>] scsi_dispatch_cmd+0xc7/0x1a0 [<000000000c119a00>] scsi_request_fn+0x251/0x550 [<000000009de0c736>] __blk_run_queue+0x3f/0x60 [<000000001c4453c8>] blk_execute_rq_nowait+0x98/0xd0 [<00000000d17ec79f>] blk_execute_rq+0x3a/0x50 [<00000000a7654b6e>] scsi_execute+0x113/0x250 [<00000000fd78f7cd>] sd_sync_cache+0x95/0x160 [<0000000024dacb14>] sd_shutdown+0x9b/0xd0 [<00000000e9101710>] sd_remove+0x5f/0xb0 [<00000000c43f0d63>] device_release_driver_internal+0x13c/0x1f0 [<00000000e8ad57b6>] bus_remove_device+0xe9/0x160 [<00000000713a7b8a>] device_del+0x120/0x320 [<00000000e5db670c>] __scsi_remove_device+0x115/0x150 [<00000000eccbef30>] scsi_forget_host+0x20/0x60 [<00000000cd5a0738>] scsi_remove_host+0x6d/0x120

Cc: stable@vger.kernel.org Signed-off-by: Luis Henriques lhenriques@suse.com

Acked-by: Douglas Gilbert dgilbert@interlog.com

Thanks.

---

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 24d7496cd9e2..364e71861bfd 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -5507,9 +5507,9 @@ static void __exit scsi_debug_exit(void) int k = sdebug_add_host; stop_all_queued();

• free_all_queued(); for (; k; k--) sdebug_remove_adapter();

• free_all_queued(); driver_unregister(&sdebug_driverfs_driver); bus_unregister(&pseudo_lld_bus); root_device_unregister(pseudo_primary);