[PATCH 3.16 050/114] libceph: make authorizer destruction independent of ceph_auth_client
From: Ben Hutchings
Date: Mon Jun 13 2016 - 14:46:27 EST
3.16.36-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Dryomov <idryomov@xxxxxxxxx>
commit 6c1ea260f89709e0021d2c59f8fd2a104b5b1123 upstream.
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@xxxxxxxxx>
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Reviewed-by: Sage Weil <sage@xxxxxxxxxx>
[bwh: Backported to 3.16:
- Implementation of ceph_x_destroy_authorizer() is different
- Adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/ceph/mds_client.c | 6 ++--
include/linux/ceph/auth.h | 10 +++---
include/linux/ceph/osd_client.h | 1 -
net/ceph/auth.c | 8 ++---
net/ceph/auth_none.c | 71 ++++++++++++++++++++++-------------------
net/ceph/auth_none.h | 3 +-
net/ceph/auth_x.c | 21 ++++++------
net/ceph/auth_x.h | 1 +
net/ceph/osd_client.c | 6 ++--
9 files changed, 62 insertions(+), 65 deletions(-)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -366,9 +366,7 @@ void ceph_put_mds_session(struct ceph_md
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);
}
}
@@ -3601,7 +3599,7 @@ static struct ceph_auth_handshake *get_a
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) {
--- a/include/linux/ceph/auth.h
+++ b/include/linux/ceph/auth.h
@@ -12,7 +12,10 @@
*/
struct ceph_auth_client;
-struct ceph_authorizer;
+
+struct ceph_authorizer {
+ void (*destroy)(struct ceph_authorizer *);
+};
struct ceph_auth_handshake {
struct ceph_authorizer *authorizer;
@@ -57,8 +60,6 @@ struct ceph_auth_client_ops {
struct ceph_auth_handshake *auth);
int (*verify_authorizer_reply)(struct ceph_auth_client *ac,
struct ceph_authorizer *a, size_t len);
- void (*destroy_authorizer)(struct ceph_auth_client *ac,
- struct ceph_authorizer *a);
void (*invalidate_authorizer)(struct ceph_auth_client *ac,
int peer_type);
@@ -102,8 +103,7 @@ extern int ceph_auth_is_authenticated(st
extern int ceph_auth_create_authorizer(struct ceph_auth_client *ac,
int peer_type,
struct ceph_auth_handshake *auth);
-extern void ceph_auth_destroy_authorizer(struct ceph_auth_client *ac,
- struct ceph_authorizer *a);
+void ceph_auth_destroy_authorizer(struct ceph_authorizer *a);
extern int ceph_auth_update_authorizer(struct ceph_auth_client *ac,
int peer_type,
struct ceph_auth_handshake *a);
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -16,7 +16,6 @@ struct ceph_msg;
struct ceph_snap_context;
struct ceph_osd_request;
struct ceph_osd_client;
-struct ceph_authorizer;
/*
* completion callback for async writepages
--- a/net/ceph/auth.c
+++ b/net/ceph/auth.c
@@ -293,13 +293,9 @@ int ceph_auth_create_authorizer(struct c
}
EXPORT_SYMBOL(ceph_auth_create_authorizer);
-void ceph_auth_destroy_authorizer(struct ceph_auth_client *ac,
- struct ceph_authorizer *a)
+void ceph_auth_destroy_authorizer(struct ceph_authorizer *a)
{
- mutex_lock(&ac->mutex);
- if (ac->ops && ac->ops->destroy_authorizer)
- ac->ops->destroy_authorizer(ac, a);
- mutex_unlock(&ac->mutex);
+ a->destroy(a);
}
EXPORT_SYMBOL(ceph_auth_destroy_authorizer);
--- a/net/ceph/auth_none.c
+++ b/net/ceph/auth_none.c
@@ -16,7 +16,6 @@ static void reset(struct ceph_auth_clien
struct ceph_auth_none_info *xi = ac->private;
xi->starting = true;
- xi->built_authorizer = false;
}
static void destroy(struct ceph_auth_client *ac)
@@ -39,6 +38,27 @@ static int should_authenticate(struct ce
return xi->starting;
}
+static int ceph_auth_none_build_authorizer(struct ceph_auth_client *ac,
+ struct ceph_none_authorizer *au)
+{
+ void *p = au->buf;
+ void *const end = p + sizeof(au->buf);
+ int ret;
+
+ ceph_encode_8_safe(&p, end, 1, e_range);
+ ret = ceph_entity_name_encode(ac->name, &p, end);
+ if (ret < 0)
+ return ret;
+
+ ceph_encode_64_safe(&p, end, ac->global_id, e_range);
+ au->buf_len = p - (void *)au->buf;
+ dout("%s built authorizer len %d\n", __func__, au->buf_len);
+ return 0;
+
+e_range:
+ return -ERANGE;
+}
+
static int build_request(struct ceph_auth_client *ac, void *buf, void *end)
{
return 0;
@@ -57,32 +77,32 @@ static int handle_reply(struct ceph_auth
return result;
}
+static void ceph_auth_none_destroy_authorizer(struct ceph_authorizer *a)
+{
+ kfree(a);
+}
+
/*
- * build an 'authorizer' with our entity_name and global_id. we can
- * reuse a single static copy since it is identical for all services
- * we connect to.
+ * build an 'authorizer' with our entity_name and global_id. it is
+ * identical for all services we connect to.
*/
static int ceph_auth_none_create_authorizer(
struct ceph_auth_client *ac, int peer_type,
struct ceph_auth_handshake *auth)
{
- struct ceph_auth_none_info *ai = ac->private;
- struct ceph_none_authorizer *au = &ai->au;
- void *p, *end;
+ struct ceph_none_authorizer *au;
int ret;
- if (!ai->built_authorizer) {
- p = au->buf;
- end = p + sizeof(au->buf);
- ceph_encode_8(&p, 1);
- ret = ceph_entity_name_encode(ac->name, &p, end - 8);
- if (ret < 0)
- goto bad;
- ceph_decode_need(&p, end, sizeof(u64), bad2);
- ceph_encode_64(&p, ac->global_id);
- au->buf_len = p - (void *)au->buf;
- ai->built_authorizer = true;
- dout("built authorizer len %d\n", au->buf_len);
+ au = kmalloc(sizeof(*au), GFP_NOFS);
+ if (!au)
+ return -ENOMEM;
+
+ au->base.destroy = ceph_auth_none_destroy_authorizer;
+
+ ret = ceph_auth_none_build_authorizer(ac, au);
+ if (ret) {
+ kfree(au);
+ return ret;
}
auth->authorizer = (struct ceph_authorizer *) au;
@@ -92,17 +112,6 @@ static int ceph_auth_none_create_authori
auth->authorizer_reply_buf_len = sizeof (au->reply_buf);
return 0;
-
-bad2:
- ret = -ERANGE;
-bad:
- return ret;
-}
-
-static void ceph_auth_none_destroy_authorizer(struct ceph_auth_client *ac,
- struct ceph_authorizer *a)
-{
- /* nothing to do */
}
static const struct ceph_auth_client_ops ceph_auth_none_ops = {
@@ -114,7 +123,6 @@ static const struct ceph_auth_client_ops
.build_request = build_request,
.handle_reply = handle_reply,
.create_authorizer = ceph_auth_none_create_authorizer,
- .destroy_authorizer = ceph_auth_none_destroy_authorizer,
};
int ceph_auth_none_init(struct ceph_auth_client *ac)
@@ -127,7 +135,6 @@ int ceph_auth_none_init(struct ceph_auth
return -ENOMEM;
xi->starting = true;
- xi->built_authorizer = false;
ac->protocol = CEPH_AUTH_NONE;
ac->private = xi;
--- a/net/ceph/auth_none.h
+++ b/net/ceph/auth_none.h
@@ -12,6 +12,7 @@
*/
struct ceph_none_authorizer {
+ struct ceph_authorizer base;
char buf[128];
int buf_len;
char reply_buf[0];
@@ -19,8 +20,6 @@ struct ceph_none_authorizer {
struct ceph_auth_none_info {
bool starting;
- bool built_authorizer;
- struct ceph_none_authorizer au; /* we only need one; it's static */
};
int ceph_auth_none_init(struct ceph_auth_client *ac);
--- a/net/ceph/auth_x.c
+++ b/net/ceph/auth_x.c
@@ -538,6 +538,14 @@ static int ceph_x_handle_reply(struct ce
return -EAGAIN;
}
+static void ceph_x_destroy_authorizer(struct ceph_authorizer *a)
+{
+ struct ceph_x_authorizer *au = (void *)a;
+
+ ceph_buffer_put(au->buf);
+ kfree(au);
+}
+
static int ceph_x_create_authorizer(
struct ceph_auth_client *ac, int peer_type,
struct ceph_auth_handshake *auth)
@@ -554,6 +562,8 @@ static int ceph_x_create_authorizer(
if (!au)
return -ENOMEM;
+ au->base.destroy = ceph_x_destroy_authorizer;
+
ret = ceph_x_build_authorizer(ac, th, au);
if (ret) {
kfree(au);
@@ -618,16 +628,6 @@ static int ceph_x_verify_authorizer_repl
return ret;
}
-static void ceph_x_destroy_authorizer(struct ceph_auth_client *ac,
- struct ceph_authorizer *a)
-{
- struct ceph_x_authorizer *au = (void *)a;
-
- ceph_buffer_put(au->buf);
- kfree(au);
-}
-
-
static void ceph_x_reset(struct ceph_auth_client *ac)
{
struct ceph_x_info *xi = ac->private;
@@ -678,7 +678,6 @@ static const struct ceph_auth_client_ops
.create_authorizer = ceph_x_create_authorizer,
.update_authorizer = ceph_x_update_authorizer,
.verify_authorizer_reply = ceph_x_verify_authorizer_reply,
- .destroy_authorizer = ceph_x_destroy_authorizer,
.invalidate_authorizer = ceph_x_invalidate_authorizer,
.reset = ceph_x_reset,
.destroy = ceph_x_destroy,
--- a/net/ceph/auth_x.h
+++ b/net/ceph/auth_x.h
@@ -26,6 +26,7 @@ struct ceph_x_ticket_handler {
struct ceph_x_authorizer {
+ struct ceph_authorizer base;
struct ceph_buffer *buf;
unsigned int service;
u64 nonce;
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -994,10 +994,8 @@ static void put_osd(struct ceph_osd *osd
dout("put_osd %p %d -> %d\n", osd, atomic_read(&osd->o_ref),
atomic_read(&osd->o_ref) - 1);
if (atomic_dec_and_test(&osd->o_ref)) {
- struct ceph_auth_client *ac = osd->o_osdc->client->monc.auth;
-
if (osd->o_auth.authorizer)
- ceph_auth_destroy_authorizer(ac, osd->o_auth.authorizer);
+ ceph_auth_destroy_authorizer(osd->o_auth.authorizer);
kfree(osd);
}
}
@@ -2873,7 +2871,7 @@ static struct ceph_auth_handshake *get_a
struct ceph_auth_handshake *auth = &o->o_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) {