On 08/06/16 07:47, Laurence Oberman wrote:
> [66814.772851] [<ffffffff8118e72f>] ? panic+0x1eb/0x233
> [66814.800207] [<ffffffff810308f8>] oops_end+0xb8/0xd0
> [66814.827454] [<ffffffff8106977e>] no_context+0x13e/0x3a0
> [66814.858368] [<ffffffff811f3feb>] ? __slab_free+0x9b/0x280
> [66814.890365] [<ffffffff81069ace>] __bad_area_nosemaphore+0xee/0x1d0
> [66814.926508] [<ffffffff81069bc4>] bad_area_nosemaphore+0x14/0x20
> [66814.959939] [<ffffffff8106a269>] __do_page_fault+0x89/0x4a0
> [66814.992039] [<ffffffff811f3feb>] ? __slab_free+0x9b/0x280
> [66815.023052] [<ffffffff8106a6b0>] do_page_fault+0x30/0x80
> [66815.053368] [<ffffffff816c8b88>] page_fault+0x28/0x30
> [66815.083196] [<ffffffff814ae4e9>] ? __scsi_remove_device+0x79/0x160
> [66815.117444] [<ffffffff814ae5c2>] ? __scsi_remove_device+0x152/0x160
> [66815.152051] [<ffffffff814ac790>] scsi_forget_host+0x60/0x70
> [66815.183939] [<ffffffff814a0137>] scsi_remove_host+0x77/0x110
> [66815.216152] [<ffffffffa0677be0>] srp_remove_work+0x90/0x200 [ib_srp]
> [66815.253221] [<ffffffff810a2e72>] process_one_work+0x152/0x400
> [66815.286221] [<ffffffff810a3765>] worker_thread+0x125/0x4b0
> [66815.317313] [<ffffffff810a3640>] ? rescuer_thread+0x380/0x380
> [66815.349770] [<ffffffff810a9298>] kthread+0xd8/0xf0
> [66815.376082] [<ffffffff816c6b3f>] ret_from_fork+0x1f/0x40
> [66815.404767] [<ffffffff810a91c0>] ? kthread_park+0x60/0x60
Hello Laurence and Johannes,
Later today I will start testing the following patch:
Subject: [PATCH] Fix a use-after-free in scsi_forget_host()
Avoid that scsi_forget_host() can call __scsi_remove_device()
while scsi_device_dev_release_usercontext() is freeing the same
SCSI device.
---
drivers/scsi/scsi_scan.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index e0a78f5..6cffc90 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1890,10 +1890,11 @@ void scsi_forget_host(struct Scsi_Host *shost)
restart:
spin_lock_irqsave(shost->host_lock, flags);
list_for_each_entry(sdev, &shost->__devices, siblings) {
- if (sdev->sdev_state == SDEV_DEL)
+ if (sdev->sdev_state == SDEV_DEL || scsi_device_get(sdev) < 0)
continue;
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_device(sdev);
+ scsi_device_put(sdev);
goto restart;
}
spin_unlock_irqrestore(shost->host_lock, flags);
--
2.9.2
--
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