linux/net/ceph
Ilya Dryomov 6c1ea260f8 libceph: make authorizer destruction independent of ceph_auth_client
Starting the kernel client with cephx disabled and then enabling cephx
and restarting userspace daemons can result in a crash:

    [262671.478162] BUG: unable to handle kernel paging request at ffffebe000000000
    [262671.531460] IP: [<ffffffff811cd04a>] kfree+0x5a/0x130
    [262671.584334] PGD 0
    [262671.635847] Oops: 0000 [#1] SMP
    [262672.055841] CPU: 22 PID: 2961272 Comm: kworker/22:2 Not tainted 4.2.0-34-generic #39~14.04.1-Ubuntu
    [262672.162338] Hardware name: Dell Inc. PowerEdge R720/068CDY, BIOS 2.4.3 07/09/2014
    [262672.268937] Workqueue: ceph-msgr con_work [libceph]
    [262672.322290] task: ffff88081c2d0dc0 ti: ffff880149ae8000 task.ti: ffff880149ae8000
    [262672.428330] RIP: 0010:[<ffffffff811cd04a>]  [<ffffffff811cd04a>] kfree+0x5a/0x130
    [262672.535880] RSP: 0018:ffff880149aeba58  EFLAGS: 00010286
    [262672.589486] RAX: 000001e000000000 RBX: 0000000000000012 RCX: ffff8807e7461018
    [262672.695980] RDX: 000077ff80000000 RSI: ffff88081af2be04 RDI: 0000000000000012
    [262672.803668] RBP: ffff880149aeba78 R08: 0000000000000000 R09: 0000000000000000
    [262672.912299] R10: ffffebe000000000 R11: ffff880819a60e78 R12: ffff8800aec8df40
    [262673.021769] R13: ffffffffc035f70f R14: ffff8807e5b138e0 R15: ffff880da9785840
    [262673.131722] FS:  0000000000000000(0000) GS:ffff88081fac0000(0000) knlGS:0000000000000000
    [262673.245377] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    [262673.303281] CR2: ffffebe000000000 CR3: 0000000001c0d000 CR4: 00000000001406e0
    [262673.417556] Stack:
    [262673.472943]  ffff880149aeba88 ffff88081af2be04 ffff8800aec8df40 ffff88081af2be04
    [262673.583767]  ffff880149aeba98 ffffffffc035f70f ffff880149aebac8 ffff8800aec8df00
    [262673.694546]  ffff880149aebac8 ffffffffc035c89e ffff8807e5b138e0 ffff8805b047f800
    [262673.805230] Call Trace:
    [262673.859116]  [<ffffffffc035f70f>] ceph_x_destroy_authorizer+0x1f/0x50 [libceph]
    [262673.968705]  [<ffffffffc035c89e>] ceph_auth_destroy_authorizer+0x3e/0x60 [libceph]
    [262674.078852]  [<ffffffffc0352805>] put_osd+0x45/0x80 [libceph]
    [262674.134249]  [<ffffffffc035290e>] remove_osd+0xae/0x140 [libceph]
    [262674.189124]  [<ffffffffc0352aa3>] __reset_osd+0x103/0x150 [libceph]
    [262674.243749]  [<ffffffffc0354703>] kick_requests+0x223/0x460 [libceph]
    [262674.297485]  [<ffffffffc03559e2>] ceph_osdc_handle_map+0x282/0x5e0 [libceph]
    [262674.350813]  [<ffffffffc035022e>] dispatch+0x4e/0x720 [libceph]
    [262674.403312]  [<ffffffffc034bd91>] try_read+0x3d1/0x1090 [libceph]
    [262674.454712]  [<ffffffff810ab7c2>] ? dequeue_entity+0x152/0x690
    [262674.505096]  [<ffffffffc034cb1b>] con_work+0xcb/0x1300 [libceph]
    [262674.555104]  [<ffffffff8108fb3e>] process_one_work+0x14e/0x3d0
    [262674.604072]  [<ffffffff810901ea>] worker_thread+0x11a/0x470
    [262674.652187]  [<ffffffff810900d0>] ? rescuer_thread+0x310/0x310
    [262674.699022]  [<ffffffff810957a2>] kthread+0xd2/0xf0
    [262674.744494]  [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0
    [262674.789543]  [<ffffffff817bd81f>] ret_from_fork+0x3f/0x70
    [262674.834094]  [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0

What happens is the following:

    (1) new MON session is established
    (2) old "none" ac is destroyed
    (3) new "cephx" ac is constructed
    ...
    (4) old OSD session (w/ "none" authorizer) is put
          ceph_auth_destroy_authorizer(ac, osd->o_auth.authorizer)

osd->o_auth.authorizer in the "none" case is just a bare pointer into
ac, which contains a single static copy for all services.  By the time
we get to (4), "none" ac, freed in (2), is long gone.  On top of that,
a new vtable installed in (3) points us at ceph_x_destroy_authorizer(),
so we end up trying to destroy a "none" authorizer with a "cephx"
destructor operating on invalid memory!

To fix this, decouple authorizer destruction from ac and do away with
a single static "none" authorizer by making a copy for each OSD or MDS
session.  Authorizers themselves are independent of ac and so there is
no reason for destroy_authorizer() to be an ac op.  Make it an op on
the authorizer itself by turning ceph_authorizer into a real struct.

Fixes: http://tracker.ceph.com/issues/15447

Reported-by: Alan Zhang <alan.zhang@linux.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2016-04-25 20:54:13 +02:00
..
crush crush: add chooseleaf_stable tunable 2016-02-04 18:25:55 +01:00
Kconfig libceph: select CRYPTO_CBC in addition to CRYPTO_AES 2014-10-14 21:03:20 +04:00
Makefile libceph: create source file "net/ceph/snapshot.c" 2013-05-01 21:20:08 -07:00
armor.c libceph: Fix base64-decoding when input ends in newline. 2011-03-15 09:14:02 -07:00
auth.c libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
auth_none.c libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
auth_none.h libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
auth_x.c libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
auth_x.h libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
auth_x_protocol.h ceph: factor out libceph from Ceph file system 2010-10-20 15:37:28 -07:00
buffer.c libceph: nuke ceph_kvfree() 2014-12-17 20:09:50 +03:00
ceph_common.c libceph: monc ping rate is 10s 2016-03-25 18:51:39 +01:00
ceph_fs.c ceph: fix file mode calculation 2011-07-19 11:25:04 -07:00
ceph_hash.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
ceph_strings.c libceph: nuke pool op infrastructure 2015-02-19 13:31:37 +03:00
crypto.c libceph: Remove unnecessary ivsize variables 2016-01-27 20:36:25 +08:00
crypto.h libceph: introduce ceph_x_authorizer_cleanup() 2015-11-02 23:36:48 +01:00
debugfs.c libceph: revamp subs code, switch to SUBSCRIBE2 protocol 2016-03-25 18:51:38 +01:00
messenger.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
mon_client.c libceph: behave in mon_fault() if cur_mon < 0 2016-03-25 18:51:40 +01:00
msgpool.c libceph: initialize msgpool message types 2012-07-30 09:29:50 -07:00
osd_client.c libceph: make authorizer destruction independent of ceph_auth_client 2016-04-25 20:54:13 +02:00
osdmap.c crush: decode and initialize chooseleaf_stable 2016-02-04 18:25:58 +01:00
pagelist.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
pagevec.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
snapshot.c libceph: create source file "net/ceph/snapshot.c" 2013-05-01 21:20:08 -07:00