Ursula Braun 5fb8642a17 net/smc: fix sock refcounting in case of termination ... When an ISM device is removed, all its linkgroups are terminated, i.e. all the corresponding connections are killed. Connection killing invokes smc_close_active_abort(), which decreases the sock refcount for certain states to simulate passive closing. And it cancels the close worker and has to give up the sock lock for this timeframe. This opens the door for a passive close worker or a socket close to run in between. In this case smc_close_active_abort() and passive close worker resp. smc_release() might do a sock_put for passive closing. This causes: [ 1323.315943] refcount_t: underflow; use-after-free. [ 1323.316055] WARNING: CPU: 3 PID: 54469 at lib/refcount.c:28 refcount_warn_saturate+0xe8/0x130 [ 1323.316069] Kernel panic - not syncing: panic_on_warn set ... [ 1323.316084] CPU: 3 PID: 54469 Comm: uperf Not tainted 5.9.0-20200826.rc2.git0.46328853ed20.300.fc32.s390x+debug #1 [ 1323.316096] Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0) [ 1323.316108] Call Trace: [ 1323.316125] [<00000000c0d4aae8>] show_stack+0x90/0xf8 [ 1323.316143] [<00000000c15989b0>] dump_stack+0xa8/0xe8 [ 1323.316158] [<00000000c0d8344e>] panic+0x11e/0x288 [ 1323.316173] [<00000000c0d83144>] __warn+0xac/0x158 [ 1323.316187] [<00000000c1597a7a>] report_bug+0xb2/0x130 [ 1323.316201] [<00000000c0d36424>] monitor_event_exception+0x44/0xc0 [ 1323.316219] [<00000000c195c716>] pgm_check_handler+0x1da/0x238 [ 1323.316234] [<00000000c151844c>] refcount_warn_saturate+0xec/0x130 [ 1323.316280] ([<00000000c1518448>] refcount_warn_saturate+0xe8/0x130) [ 1323.316310] [<000003ff801f2e2a>] smc_release+0x192/0x1c8 [smc] [ 1323.316323] [<00000000c169f1fa>] __sock_release+0x5a/0xe0 [ 1323.316334] [<00000000c169f2ac>] sock_close+0x2c/0x40 [ 1323.316350] [<00000000c1086de0>] __fput+0xb8/0x278 [ 1323.316362] [<00000000c0db1e0e>] task_work_run+0x76/0xb8 [ 1323.316393] [<00000000c0d8ab84>] do_exit+0x26c/0x520 [ 1323.316408] [<00000000c0d8af08>] do_group_exit+0x48/0xc0 [ 1323.316421] [<00000000c0d8afa8>] __s390x_sys_exit_group+0x28/0x38 [ 1323.316433] [<00000000c195c32c>] system_call+0xe0/0x2b4 [ 1323.316446] 1 lock held by uperf/54469: [ 1323.316456] #0: 0000000044125e60 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release+0x44/0xe0 The patch rechecks sock state in smc_close_active_abort() after smc_close_cancel_work() to avoid duplicate decrease of sock refcount for the same purpose. Fixes: 611b63a127 ("net/smc: cancel tx worker in case of socket aborts") Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2020-09-03 16:52:33 -07:00
..
af_smc.c	net/smc: unique reason code for exceeded max dmb count	2020-07-27 10:30:01 -07:00
Kconfig	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
smc_cdc.c	net/smc: put slot when connection is killed	2020-07-20 17:52:25 -07:00
smc_cdc.h	net/smc: pre-fetch send buffer outside of send_lock	2020-05-30 18:12:25 -07:00
smc_clc.c	net/smc: tolerate future SMCD versions	2020-07-08 12:35:15 -07:00
smc_clc.h	net/smc: unique reason code for exceeded max dmb count	2020-07-27 10:30:01 -07:00
smc_close.c	net/smc: fix sock refcounting in case of termination	2020-09-03 16:52:33 -07:00
smc_close.h	net/smc: remove close abort worker	2019-10-22 11:23:44 -07:00
smc_core.c	net/smc: reset sndbuf_desc if freed	2020-09-03 16:52:33 -07:00
smc_core.h	net/smc: do not call dma sync for unmapped memory	2020-07-19 15:30:22 -07:00
smc_diag.c	net/smc: Prevent kernel-infoleak in __smc_diag_dump()	2020-08-20 12:07:31 -07:00
smc_ib.c	net/smc: protect smc ib device initialization	2020-07-19 15:30:22 -07:00
smc_ib.h	net/smc: protect smc ib device initialization	2020-07-19 15:30:22 -07:00
smc_ism.c	net/smc: switch smcd_dev_list spinlock to mutex	2020-07-08 12:35:15 -07:00
smc_ism.h	net/smc: switch smcd_dev_list spinlock to mutex	2020-07-08 12:35:15 -07:00
smc_llc.c	net/smc: fix toleration of fake add_link messages	2020-09-03 16:52:33 -07:00
smc_llc.h	net/smc: move add link processing for new device into llc layer	2020-07-19 15:30:22 -07:00
smc_netns.h	net/smc: add pnet table namespace support	2019-02-21 10:34:37 -08:00
smc_pnet.c	net/smc: switch smcd_dev_list spinlock to mutex	2020-07-08 12:35:15 -07:00
smc_pnet.h	net/smc: introduce smc_pnet_find_alt_roce()	2020-05-01 16:20:05 -07:00
smc_rx.c	fs: make the pipe_buf_operations ->confirm operation optional	2020-05-20 12:11:26 -04:00
smc_rx.h	smc: add support for splice()	2018-05-04 11:45:06 -04:00
smc_tx.c	net/smc: switch connections to alternate link	2020-05-04 10:54:39 -07:00
smc_tx.h	net/smc: eliminate cursor read and write calls	2018-07-23 10:57:14 -07:00
smc_wr.c	net/smc: fix work request handling	2020-07-08 12:35:15 -07:00
smc_wr.h	net/smc: wait for departure of an IB message	2020-05-04 10:54:39 -07:00
smc.h	net/smc: handle incoming CDC validation message	2020-05-04 10:54:39 -07:00