linux/net/xfrm
YueHaibing 4c59406ed0 xfrm: policy: Fix doulbe free in xfrm_policy_timer
After xfrm_add_policy add a policy, its ref is 2, then

                             xfrm_policy_timer
                               read_lock
                               xp->walk.dead is 0
                               ....
                               mod_timer()
xfrm_policy_kill
  policy->walk.dead = 1
  ....
  del_timer(&policy->timer)
    xfrm_pol_put //ref is 1
  xfrm_pol_put  //ref is 0
    xfrm_policy_destroy
      call_rcu
                                 xfrm_pol_hold //ref is 1
                               read_unlock
                               xfrm_pol_put //ref is 0
                                 xfrm_policy_destroy
                                  call_rcu

xfrm_policy_destroy is called twice, which may leads to
double free.

Call Trace:
RIP: 0010:refcount_warn_saturate+0x161/0x210
...
 xfrm_policy_timer+0x522/0x600
 call_timer_fn+0x1b3/0x5e0
 ? __xfrm_decode_session+0x2990/0x2990
 ? msleep+0xb0/0xb0
 ? _raw_spin_unlock_irq+0x24/0x40
 ? __xfrm_decode_session+0x2990/0x2990
 ? __xfrm_decode_session+0x2990/0x2990
 run_timer_softirq+0x5c5/0x10e0

Fix this by use write_lock_bh in xfrm_policy_kill.

Fixes: ea2dea9dac ("xfrm: remove policy lock when accessing policy->walk.dead")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Timo Teräs <timo.teras@iki.fi>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2020-03-24 06:56:54 +01:00
..
espintcp.c xfrm: add espintcp (RFC 8229) 2019-12-09 09:59:07 +01:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-11-25 20:02:57 -08:00
Makefile xfrm: add espintcp (RFC 8229) 2019-12-09 09:59:07 +01:00
xfrm_algo.c crypto: skcipher - remove the "blkcipher" algorithm type 2019-11-01 13:38:32 +08:00
xfrm_device.c esp: remove the skb from the chain when it's enqueued in cryptd_wq 2020-03-04 12:41:29 +01:00
xfrm_hash.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
xfrm_hash.h xfrm: use complete IPv6 addresses for hash 2018-10-15 10:09:18 +02:00
xfrm_inout.h xfrm: remove input2 indirection from xfrm_mode 2019-04-08 09:14:55 +02:00
xfrm_input.c xfrm: introduce xfrm_trans_queue_net 2019-12-09 09:59:07 +01:00
xfrm_interface.c xfrm: interface: do not confirm neighbor when do pmtu update 2020-01-14 08:55:38 +01:00
xfrm_ipcomp.c net: Use skb_frag_off accessors 2019-07-30 14:21:32 -07:00
xfrm_output.c net: xfrm: use skb_list_walk_safe helper for gso segments 2020-01-14 11:48:41 -08:00
xfrm_policy.c xfrm: policy: Fix doulbe free in xfrm_policy_timer 2020-03-24 06:56:54 +01:00
xfrm_proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
xfrm_replay.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335 2019-06-05 17:37:06 +02:00
xfrm_state.c xfrm: add espintcp (RFC 8229) 2019-12-09 09:59:07 +01:00
xfrm_sysctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm_user.c xfrm: add the missing verify_sec_ctx_len check in xfrm_add_acquire 2020-02-12 11:06:32 +01:00