• Luis Henriques's avatar
    scsi: scsi_debug: Fix memory leak on module unload · 52ab9768
    Luis Henriques authored
    Since commit 80c49563 ("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 # v4.17+
    Signed-off-by: default avatarLuis Henriques <lhenriques@suse.com>
    Acked-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    52ab9768
scsi_debug.c 174 KB