Duoming Zhou 7d8a3a477b ax25: Fix ax25 session cleanup problems ... There are session cleanup problems in ax25_release() and ax25_disconnect(). If we setup a session and then disconnect, the disconnected session is still in "LISTENING" state that is shown below. Active AX.25 sockets Dest Source Device State Vr/Vs Send-Q Recv-Q DL9SAU-4 DL9SAU-3 ??? LISTENING 000/000 0 0 DL9SAU-3 DL9SAU-4 ??? LISTENING 000/000 0 0 The first reason is caused by del_timer_sync() in ax25_release(). The timers of ax25 are used for correct session cleanup. If we use ax25_release() to close ax25 sessions and ax25_dev is not null, the del_timer_sync() functions in ax25_release() will execute. As a result, the sessions could not be cleaned up correctly, because the timers have stopped. In order to solve this problem, this patch adds a device_up flag in ax25_dev in order to judge whether the device is up. If there are sessions to be cleaned up, the del_timer_sync() in ax25_release() will not execute. What's more, we add ax25_cb_del() in ax25_kill_by_device(), because the timers have been stopped and there are no functions that could delete ax25_cb if we do not call ax25_release(). Finally, we reorder the position of ax25_list_lock in ax25_cb_del() in order to synchronize among different functions that call ax25_cb_del(). The second reason is caused by improper check in ax25_disconnect(). The incoming ax25 sessions which ax25->sk is null will close heartbeat timer, because the check "if(!ax25->sk || ..)" is satisfied. As a result, the session could not be cleaned up properly. In order to solve this problem, this patch changes the improper check to "if(ax25->sk && ..)" in ax25_disconnect(). What`s more, the ax25_disconnect() may be called twice, which is not necessary. For example, ax25_kill_by_device() calls ax25_disconnect() and sets ax25->state to AX25_STATE_0, but ax25_release() calls ax25_disconnect() again. In order to solve this problem, this patch add a check in ax25_release(). If the flag of ax25->sk equals to SOCK_DEAD, the ax25_disconnect() in ax25_release() should not be executed. Fixes: 82e31755e5 ("ax25: Fix UAF bugs in ax25 timers") Fixes: 8a367e74c0 ("ax25: Fix segfault after sock connection timeout") Reported-and-tested-by: Thomas Osterried <thomas@osterried.de> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20220530152158.108619-1-duoming@zju.edu.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com>		2022-06-02 10:37:57 +02:00
..
acpi	Power management updates for 5.19-rc1	2022-05-24 16:04:25 -07:00
asm-generic	Scheduler changes in this cycle were:	2022-05-24 11:11:13 -07:00
clocksource
crypto
drm
dt-bindings	dt-bindings: clk: mpfs: add defines for two new clocks	2022-04-22 18:40:15 -07:00
keys	KEYS: trusted: Introduce support for NXP CAAM-based trusted keys	2022-05-23 18:47:50 +03:00
kunit	kunit: take kunit_assert as const	2022-05-16 13:23:00 -06:00
kvm
linux	net/mlx5: correct ECE offset in query qp output	2022-05-31 13:40:54 -07:00
math-emu
media	media: h264: Sort p/b reflist using frame_num	2022-05-17 10:02:29 +02:00
memory	memory: renesas-rpc-if: Fix HF/OSPI data transfer in Manual Mode	2022-04-21 17:00:24 +02:00
misc
net	ax25: Fix ax25 session cleanup problems	2022-06-02 10:37:57 +02:00
pcmcia
ras
rdma
scsi
soc	Networking changes for 5.19.	2022-05-25 12:22:58 -07:00
sound	ASoC: Fixes for v5.18	2022-04-19 17:26:01 +02:00
target	target: pass a block_device to target_configure_unmap_from_queue	2022-04-17 19:49:58 -06:00
trace	Networking changes for 5.19.	2022-05-25 12:22:58 -07:00
uapi	socket: Don't use u8 type in uapi socket.h	2022-06-01 16:48:05 -07:00
vdso
video
xen	xen: sync xs_wire.h header with upstream xen	2022-05-19 14:44:05 +02:00