commit 6a0990eaa7 upstream.
Clearing ch->device in ch_release() is wrong because that pointer must
remain valid until ch_remove() is called. This patch fixes the following
crash the second time a ch device is opened:
BUG: kernel NULL pointer dereference, address: 0000000000000790
RIP: 0010:scsi_device_get+0x5/0x60
Call Trace:
ch_open+0x4c/0xa0 [ch]
chrdev_open+0xa2/0x1c0
do_dentry_open+0x13a/0x380
path_openat+0x591/0x1470
do_filp_open+0x91/0x100
do_sys_open+0x184/0x220
do_syscall_64+0x5f/0x1a0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 085e56766f ("scsi: ch: add refcounting")
Cc: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191009173536.247889-1-bvanassche@acm.org
Reported-by: Rob Turk <robtu@rtist.nl>
Suggested-by: Rob Turk <robtu@rtist.nl>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bart Van Assche
e254d43592