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author | Ilya Dryomov <idryomov@gmail.com> | 2016-04-11 19:34:49 +0200 |
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committer | Ilya Dryomov <idryomov@gmail.com> | 2016-04-25 20:54:13 +0200 |
commit | 6c1ea260f89709e0021d2c59f8fd2a104b5b1123 (patch) | |
tree | 6d31111c823ad63d117da9edd02c7ae700f05476 /fs | |
parent | 02da2d72174c61988eb4456b53f405e3ebdebce4 (diff) | |
download | linux-6c1ea260f89709e0021d2c59f8fd2a104b5b1123.tar.gz linux-6c1ea260f89709e0021d2c59f8fd2a104b5b1123.tar.bz2 linux-6c1ea260f89709e0021d2c59f8fd2a104b5b1123.zip |
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>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ceph/mds_client.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 541ead4d8965..85b8517f17a0 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -386,9 +386,7 @@ void ceph_put_mds_session(struct ceph_mds_session *s) atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1); if (atomic_dec_and_test(&s->s_ref)) { if (s->s_auth.authorizer) - ceph_auth_destroy_authorizer( - s->s_mdsc->fsc->client->monc.auth, - s->s_auth.authorizer); + ceph_auth_destroy_authorizer(s->s_auth.authorizer); kfree(s); } } @@ -3900,7 +3898,7 @@ static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con, struct ceph_auth_handshake *auth = &s->s_auth; if (force_new && auth->authorizer) { - ceph_auth_destroy_authorizer(ac, auth->authorizer); + ceph_auth_destroy_authorizer(auth->authorizer); auth->authorizer = NULL; } if (!auth->authorizer) { |