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| author | Stefan Haberland <sth@linux.vnet.ibm.com> | 2016-09-20 11:42:38 +0300 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2016-09-26 17:45:29 +0300 |
| commit | c020d722b110a44c613ef71e657e6dd4116e09d9 (patch) | |
| tree | 5fc0f6d62335cb7075f6a162380ee54c1b3ea069 /drivers/s390/block/dasd_devmap.c | |
| parent | a9f6273ff9c80dd2c226f7a2d5c16272e5092d3e (diff) | |
| download | linux-c020d722b110a44c613ef71e657e6dd4116e09d9.tar.xz | |
s390/dasd: fix panic during offline processing
A DASD device consists of the device itself and a discipline with a
corresponding private structure. These fields are set up during online
processing right after the device is created and before it is processed by
the state machine and made available for I/O.
During offline processing the discipline pointer and the private data gets
freed within the state machine and without protection of the existing
reference count. This might lead to a kernel panic because a function might
have taken a device reference and accesses the discipline pointer and/or
private data of the device while this is already freed.
Fix by freeing the discipline pointer and the private data after ensuring
that there is no reference to the device left.
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/block/dasd_devmap.c')
| -rw-r--r-- | drivers/s390/block/dasd_devmap.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index 3cdbce45e464..15a1a70cace9 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -617,6 +617,7 @@ dasd_delete_device(struct dasd_device *device) /* Wait for reference counter to drop to zero. */ wait_event(dasd_delete_wq, atomic_read(&device->ref_count) == 0); + dasd_generic_free_discipline(device); /* Disconnect dasd_device structure from ccw_device structure. */ cdev = device->cdev; device->cdev = NULL; |