Bart Van Assche e254d43592 scsi: ch: Make it possible to open a ch device multiple times again
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>
2019-10-29 09:19:50 +01:00
2019-10-29 09:19:43 +01:00
2019-10-17 13:45:44 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
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See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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