forked from Minki/linux
082a1532fc
rfcomm_dev_get() can return a rfcomm_dev reference for a
device for which destruction may be commencing. This can happen
on tty destruction, which calls rfcomm_tty_cleanup(), the last
port reference may have been released but RFCOMM_TTY_RELEASED
was not set. The following race is also possible:
CPU 0 | CPU 1
| rfcomm_release_dev
rfcomm_dev_get | .
spin_lock | .
dev = __rfcomm_dev_get | .
if dev | .
if test_bit(TTY_RELEASED) | .
| !test_and_set_bit(TTY_RELEASED)
| tty_port_put <<<< last reference
else |
tty_port_get |
The reference acquire is bogus because destruction will commence
with the release of the last reference.
Ignore the external state change of TTY_RELEASED and instead rely
on the reference acquire itself to determine if the reference is
valid.
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
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|---|---|---|
| .. | ||
| bnep | ||
| cmtp | ||
| hidp | ||
| rfcomm | ||
| 6lowpan.c | ||
| 6lowpan.h | ||
| a2mp.c | ||
| a2mp.h | ||
| af_bluetooth.c | ||
| amp.c | ||
| amp.h | ||
| hci_conn.c | ||
| hci_core.c | ||
| hci_event.c | ||
| hci_sock.c | ||
| hci_sysfs.c | ||
| Kconfig | ||
| l2cap_core.c | ||
| l2cap_sock.c | ||
| lib.c | ||
| Makefile | ||
| mgmt.c | ||
| sco.c | ||
| smp.c | ||
| smp.h | ||