diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2012-06-21 23:47:28 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-09 08:31:28 -0700 |
| commit | f07d3f59e35eb0fc8847587f601f84b8cfa8dd38 (patch) | |
| tree | 595db5361b5b316648b0d3b9bea7a4daf4ccd0a0 /drivers/scsi/scsi_scan.c | |
| parent | bb12049078a3a69f750779a19287cd4ac5f2bc3e (diff) | |
SCSI: fix hot unplug vs async scan race
commit 3b661a92e869ebe2358de8f4b3230ad84f7fce51 upstream.
The following crash results from cases where the end_device has been
removed before scsi_sysfs_add_sdev has had a chance to run.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000098
IP: [<ffffffff8115e100>] sysfs_create_dir+0x32/0xb6
...
Call Trace:
[<ffffffff8125e4a8>] kobject_add_internal+0x120/0x1e3
[<ffffffff81075149>] ? trace_hardirqs_on+0xd/0xf
[<ffffffff8125e641>] kobject_add_varg+0x41/0x50
[<ffffffff8125e70b>] kobject_add+0x64/0x66
[<ffffffff8131122b>] device_add+0x12d/0x63a
[<ffffffff814b65ea>] ? _raw_spin_unlock_irqrestore+0x47/0x56
[<ffffffff8107de15>] ? module_refcount+0x89/0xa0
[<ffffffff8132f348>] scsi_sysfs_add_sdev+0x4e/0x28a
[<ffffffff8132dcbb>] do_scan_async+0x9c/0x145
...teach scsi_sysfs_add_devices() to check for deleted devices() before
trying to add them, and teach scsi_remove_target() how to remove targets
that have not been added via device_add().
Reported-by: Dariusz Majchrzak <dariusz.majchrzak@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi/scsi_scan.c')
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 01b03744f1f9..8906557d2a24 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -1714,6 +1714,9 @@ static void scsi_sysfs_add_devices(struct Scsi_Host *shost) { struct scsi_device *sdev; shost_for_each_device(sdev, shost) { + /* target removed before the device could be added */ + if (sdev->sdev_state == SDEV_DEL) + continue; if (!scsi_host_scan_allowed(shost) || scsi_sysfs_add_sdev(sdev) != 0) __scsi_remove_device(sdev); |