TencentOS-kernel/drivers/s390
Stefan Haberland 552b5406e2 s390/dasd: fix list corruption of lcu list
commit 53a7f655834c7c335bf683f248208d4fbe4b47bc upstream.

In dasd_alias_disconnect_device_from_lcu the device is removed from any
list on the LCU. Afterwards the LCU is removed from the lcu list if it
does not contain devices any longer.

The lcu->lock protects the lcu from parallel updates. But to cancel all
workers and wait for completion the lcu->lock has to be unlocked.

If two devices are removed in parallel and both are removed from the LCU
the first device that takes the lcu->lock again will delete the LCU because
it is already empty but the second device also tries to free the LCU which
leads to a list corruption of the lcu list.

Fix by removing the device right before the lcu is checked without
unlocking the lcu->lock in between.

Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:43:28 +08:00
..
block s390/dasd: fix list corruption of lcu list 2021-03-16 16:43:28 +08:00
char Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
cio s390/cio: fix use-after-free in ccw_device_destroy_console 2021-03-16 16:43:10 +08:00
crypto s390/pkey: fix paes selftest failure with paes and pkey static build 2021-03-16 16:40:28 +08:00
net s390/qeth: fix tear down of async TX buffers 2021-03-16 16:41:43 +08:00
scsi scsi: zfcp: Fix use-after-free in request timeout handlers 2021-03-16 16:34:30 +08:00
virtio Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00
Makefile Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces. 2021-03-16 11:01:34 +08:00