![Ilya Dryomov](/assets/img/avatar_default.png)
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>
145 lines
3 KiB
C
145 lines
3 KiB
C
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#include <linux/ceph/ceph_debug.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/slab.h>
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#include <linux/ceph/decode.h>
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#include <linux/ceph/auth.h>
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#include "auth_none.h"
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static void reset(struct ceph_auth_client *ac)
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{
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struct ceph_auth_none_info *xi = ac->private;
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xi->starting = true;
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}
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static void destroy(struct ceph_auth_client *ac)
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{
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kfree(ac->private);
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ac->private = NULL;
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}
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static int is_authenticated(struct ceph_auth_client *ac)
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{
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struct ceph_auth_none_info *xi = ac->private;
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return !xi->starting;
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}
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static int should_authenticate(struct ceph_auth_client *ac)
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{
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struct ceph_auth_none_info *xi = ac->private;
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return xi->starting;
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}
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static int ceph_auth_none_build_authorizer(struct ceph_auth_client *ac,
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struct ceph_none_authorizer *au)
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{
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void *p = au->buf;
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void *const end = p + sizeof(au->buf);
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int ret;
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ceph_encode_8_safe(&p, end, 1, e_range);
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ret = ceph_entity_name_encode(ac->name, &p, end);
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if (ret < 0)
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return ret;
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ceph_encode_64_safe(&p, end, ac->global_id, e_range);
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au->buf_len = p - (void *)au->buf;
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dout("%s built authorizer len %d\n", __func__, au->buf_len);
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return 0;
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e_range:
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return -ERANGE;
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}
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static int build_request(struct ceph_auth_client *ac, void *buf, void *end)
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{
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return 0;
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}
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/*
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* the generic auth code decode the global_id, and we carry no actual
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* authenticate state, so nothing happens here.
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*/
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static int handle_reply(struct ceph_auth_client *ac, int result,
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void *buf, void *end)
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{
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struct ceph_auth_none_info *xi = ac->private;
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xi->starting = false;
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return result;
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}
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static void ceph_auth_none_destroy_authorizer(struct ceph_authorizer *a)
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{
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kfree(a);
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}
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/*
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* build an 'authorizer' with our entity_name and global_id. it is
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* identical for all services we connect to.
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*/
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static int ceph_auth_none_create_authorizer(
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struct ceph_auth_client *ac, int peer_type,
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struct ceph_auth_handshake *auth)
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{
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struct ceph_none_authorizer *au;
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int ret;
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au = kmalloc(sizeof(*au), GFP_NOFS);
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if (!au)
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return -ENOMEM;
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au->base.destroy = ceph_auth_none_destroy_authorizer;
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ret = ceph_auth_none_build_authorizer(ac, au);
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if (ret) {
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kfree(au);
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return ret;
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}
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auth->authorizer = (struct ceph_authorizer *) au;
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auth->authorizer_buf = au->buf;
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auth->authorizer_buf_len = au->buf_len;
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auth->authorizer_reply_buf = au->reply_buf;
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auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
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return 0;
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}
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static const struct ceph_auth_client_ops ceph_auth_none_ops = {
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.name = "none",
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.reset = reset,
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.destroy = destroy,
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.is_authenticated = is_authenticated,
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.should_authenticate = should_authenticate,
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.build_request = build_request,
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.handle_reply = handle_reply,
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.create_authorizer = ceph_auth_none_create_authorizer,
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};
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int ceph_auth_none_init(struct ceph_auth_client *ac)
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{
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struct ceph_auth_none_info *xi;
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dout("ceph_auth_none_init %p\n", ac);
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xi = kzalloc(sizeof(*xi), GFP_NOFS);
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if (!xi)
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return -ENOMEM;
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xi->starting = true;
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ac->protocol = CEPH_AUTH_NONE;
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ac->private = xi;
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ac->ops = &ceph_auth_none_ops;
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return 0;
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}
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