android_kernel_oneplus_msm8998/net/ceph
Ilya Dryomov 2e9e4e1590 libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive()
commit 4aac9228d16458cedcfd90c7fb37211cf3653ac3 upstream.

con_fault() can transition the connection into STANDBY right after
ceph_con_keepalive() clears STANDBY in clear_standby():

    libceph user thread               ceph-msgr worker

ceph_con_keepalive()
  mutex_lock(&con->mutex)
  clear_standby(con)
  mutex_unlock(&con->mutex)
                                mutex_lock(&con->mutex)
                                con_fault()
                                  ...
                                  if KEEPALIVE_PENDING isn't set
                                    set state to STANDBY
                                  ...
                                mutex_unlock(&con->mutex)
  set KEEPALIVE_PENDING
  set WRITE_PENDING

This triggers warnings in clear_standby() when either ceph_con_send()
or ceph_con_keepalive() get to clearing STANDBY next time.

I don't see a reason to condition queue_con() call on the previous
value of KEEPALIVE_PENDING, so move the setting of KEEPALIVE_PENDING
into the critical section -- unlike WRITE_PENDING, KEEPALIVE_PENDING
could have been a non-atomic flag.

Reported-by: syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-20 10:13:20 +01:00
..
crush crush: sync up with userspace 2015-06-25 11:49:31 +03:00
armor.c
auth.c
auth_none.c
auth_none.h
auth_x.c libceph: add nocephx_sign_messages option 2015-11-02 23:37:46 +01:00
auth_x.h libceph: store session key in cephx authorizer 2014-12-17 20:09:50 +03:00
auth_x_protocol.h
buffer.c libceph: nuke ceph_kvfree() 2014-12-17 20:09:50 +03:00
ceph_common.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2015-11-13 09:24:40 -08:00
ceph_fs.c
ceph_hash.c
ceph_strings.c libceph: nuke pool op infrastructure 2015-02-19 13:31:37 +03:00
crypto.c KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00
crypto.h libceph: introduce ceph_x_authorizer_cleanup() 2015-11-02 23:36:48 +01:00
debugfs.c libceph: expose client options through debugfs 2015-04-20 18:55:39 +03:00
Kconfig libceph: select CRYPTO_CBC in addition to CRYPTO_AES 2014-10-14 21:03:20 +04:00
Makefile
messenger.c libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive() 2019-02-20 10:13:20 +01:00
mon_client.c libceph: use keepalive2 to verify the mon session is alive 2015-09-08 23:14:30 +03:00
msgpool.c
osd_client.c libceph: don't spam dmesg with stray reply warnings 2016-03-03 15:07:26 -08:00
osdmap.c libceph: NULL deref on crush_decode() error path 2018-04-13 19:50:10 +02:00
pagelist.c libceph: reference counting pagelist 2014-10-14 12:56:48 -07:00
pagevec.c mm: replace get_user_pages_unlocked() write/force parameters with gup_flags 2018-12-17 21:55:16 +01:00
snapshot.c