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alistair23-linux/fs/afs/cmservice.c
David Howells 6c67c7c38c AFS: Fix cache manager service handlers 
Fix the cache manager RPC service handlers.  The afs_send_empty_reply() and
afs_send_simple_reply() functions:

 (a) Kill the call and free up the buffers associated with it if they fail.

 (b) Return with call intact if it they succeed.

However, none of the callers actually check the result or clean up if
successful - and may use the now non-existent data if it fails.

This was detected by Dan Carpenter using a static checker:

	The patch 08e0e7c82e: "[AF_RXRPC]: Make the in-kernel AFS
	filesystem use AF_RXRPC." from Apr 26, 2007, leads to the following
	static checker warning:
	"fs/afs/cmservice.c:155 SRXAFSCB_CallBack()
		 warn: 'call' was already freed."

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-05-21 14:48:05 +01:00

605 lines
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/* AFS Cache Manager Service
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/ip.h>
#include "internal.h"
#include "afs_cm.h"
#if 0
struct workqueue_struct *afs_cm_workqueue;
#endif /* 0 */
static int afs_deliver_cb_init_call_back_state(struct afs_call *,
struct sk_buff *, bool);
static int afs_deliver_cb_init_call_back_state3(struct afs_call *,
struct sk_buff *, bool);
static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_probe_uuid(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *,
struct sk_buff *, bool);
static void afs_cm_destructor(struct afs_call *);
/*
* CB.CallBack operation type
*/
static const struct afs_call_type afs_SRXCBCallBack = {
.name = "CB.CallBack",
.deliver = afs_deliver_cb_callback,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.InitCallBackState operation type
*/
static const struct afs_call_type afs_SRXCBInitCallBackState = {
.name = "CB.InitCallBackState",
.deliver = afs_deliver_cb_init_call_back_state,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.InitCallBackState3 operation type
*/
static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
.name = "CB.InitCallBackState3",
.deliver = afs_deliver_cb_init_call_back_state3,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.Probe operation type
*/
static const struct afs_call_type afs_SRXCBProbe = {
.name = "CB.Probe",
.deliver = afs_deliver_cb_probe,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.ProbeUuid operation type
*/
static const struct afs_call_type afs_SRXCBProbeUuid = {
.name = "CB.ProbeUuid",
.deliver = afs_deliver_cb_probe_uuid,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* CB.TellMeAboutYourself operation type
*/
static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
.name = "CB.TellMeAboutYourself",
.deliver = afs_deliver_cb_tell_me_about_yourself,
.abort_to_error = afs_abort_to_error,
.destructor = afs_cm_destructor,
};
/*
* route an incoming cache manager call
* - return T if supported, F if not
*/
bool afs_cm_incoming_call(struct afs_call *call)
{
u32 operation_id = ntohl(call->operation_ID);
_enter("{CB.OP %u}", operation_id);
switch (operation_id) {
case CBCallBack:
call->type = &afs_SRXCBCallBack;
return true;
case CBInitCallBackState:
call->type = &afs_SRXCBInitCallBackState;
return true;
case CBInitCallBackState3:
call->type = &afs_SRXCBInitCallBackState3;
return true;
case CBProbe:
call->type = &afs_SRXCBProbe;
return true;
case CBTellMeAboutYourself:
call->type = &afs_SRXCBTellMeAboutYourself;
return true;
default:
return false;
}
}
/*
* clean up a cache manager call
*/
static void afs_cm_destructor(struct afs_call *call)
{
_enter("");
/* Break the callbacks here so that we do it after the final ACK is
* received. The step number here must match the final number in
* afs_deliver_cb_callback().
*/
if (call->unmarshall == 6) {
ASSERT(call->server && call->count && call->request);
afs_break_callbacks(call->server, call->count, call->request);
}
afs_put_server(call->server);
call->server = NULL;
kfree(call->buffer);
call->buffer = NULL;
}
/*
* allow the fileserver to see if the cache manager is still alive
*/
static void SRXAFSCB_CallBack(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
/* be sure to send the reply *before* attempting to spam the AFS server
* with FSFetchStatus requests on the vnodes with broken callbacks lest
* the AFS server get into a vicious cycle of trying to break further
* callbacks because it hadn't received completion of the CBCallBack op
* yet */
afs_send_empty_reply(call);
afs_break_callbacks(call->server, call->count, call->request);
_leave("");
}
/*
* deliver request data to a CB.CallBack call
*/
static int afs_deliver_cb_callback(struct afs_call *call, struct sk_buff *skb,
bool last)
{
struct afs_callback *cb;
struct afs_server *server;
struct in_addr addr;
__be32 *bp;
u32 tmp;
int ret, loop;
_enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
switch (call->unmarshall) {
case 0:
call->offset = 0;
call->unmarshall++;
/* extract the FID array and its count in two steps */
case 1:
_debug("extract FID count");
ret = afs_extract_data(call, skb, last, &call->tmp, 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
call->count = ntohl(call->tmp);
_debug("FID count: %u", call->count);
if (call->count > AFSCBMAX)
return -EBADMSG;
call->buffer = kmalloc(call->count * 3 * 4, GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
call->offset = 0;
call->unmarshall++;
case 2:
_debug("extract FID array");
ret = afs_extract_data(call, skb, last, call->buffer,
call->count * 3 * 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall FID array");
call->request = kcalloc(call->count,
sizeof(struct afs_callback),
GFP_KERNEL);
if (!call->request)
return -ENOMEM;
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->fid.vid = ntohl(*bp++);
cb->fid.vnode = ntohl(*bp++);
cb->fid.unique = ntohl(*bp++);
cb->type = AFSCM_CB_UNTYPED;
}
call->offset = 0;
call->unmarshall++;
/* extract the callback array and its count in two steps */
case 3:
_debug("extract CB count");
ret = afs_extract_data(call, skb, last, &call->tmp, 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
tmp = ntohl(call->tmp);
_debug("CB count: %u", tmp);
if (tmp != call->count && tmp != 0)
return -EBADMSG;
call->offset = 0;
call->unmarshall++;
if (tmp == 0)
goto empty_cb_array;
case 4:
_debug("extract CB array");
ret = afs_extract_data(call, skb, last, call->request,
call->count * 3 * 4);
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall CB array");
cb = call->request;
bp = call->buffer;
for (loop = call->count; loop > 0; loop--, cb++) {
cb->version = ntohl(*bp++);
cb->expiry = ntohl(*bp++);
cb->type = ntohl(*bp++);
}
empty_cb_array:
call->offset = 0;
call->unmarshall++;
case 5:
_debug("trailer");
if (skb->len != 0)
return -EBADMSG;
/* Record that the message was unmarshalled successfully so
* that the call destructor can know do the callback breaking
* work, even if the final ACK isn't received.
*
* If the step number changes, then afs_cm_destructor() must be
* updated also.
*/
call->unmarshall++;
case 6:
break;
}
if (!last)
return 0;
call->state = AFS_CALL_REPLYING;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
memcpy(&addr, &ip_hdr(skb)->saddr, 4);
server = afs_find_server(&addr);
if (!server)
return -ENOTCONN;
call->server = server;
INIT_WORK(&call->work, SRXAFSCB_CallBack);
queue_work(afs_wq, &call->work);
return 0;
}
/*
* allow the fileserver to request callback state (re-)initialisation
*/
static void SRXAFSCB_InitCallBackState(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("{%p}", call->server);
afs_init_callback_state(call->server);
afs_send_empty_reply(call);
_leave("");
}
/*
* deliver request data to a CB.InitCallBackState call
*/
static int afs_deliver_cb_init_call_back_state(struct afs_call *call,
struct sk_buff *skb,
bool last)
{
struct afs_server *server;
struct in_addr addr;
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
memcpy(&addr, &ip_hdr(skb)->saddr, 4);
server = afs_find_server(&addr);
if (!server)
return -ENOTCONN;
call->server = server;
INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
queue_work(afs_wq, &call->work);
return 0;
}
/*
* deliver request data to a CB.InitCallBackState3 call
*/
static int afs_deliver_cb_init_call_back_state3(struct afs_call *call,
struct sk_buff *skb,
bool last)
{
struct afs_server *server;
struct in_addr addr;
_enter(",{%u},%d", skb->len, last);
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
memcpy(&addr, &ip_hdr(skb)->saddr, 4);
server = afs_find_server(&addr);
if (!server)
return -ENOTCONN;
call->server = server;
INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
queue_work(afs_wq, &call->work);
return 0;
}
/*
* allow the fileserver to see if the cache manager is still alive
*/
static void SRXAFSCB_Probe(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
_enter("");
afs_send_empty_reply(call);
_leave("");
}
/*
* deliver request data to a CB.Probe call
*/
static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb,
bool last)
{
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
INIT_WORK(&call->work, SRXAFSCB_Probe);
queue_work(afs_wq, &call->work);
return 0;
}
/*
* allow the fileserver to quickly find out if the fileserver has been rebooted
*/
static void SRXAFSCB_ProbeUuid(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, work);
struct afs_uuid *r = call->request;
struct {
__be32 match;
} reply;
_enter("");
if (memcmp(r, &afs_uuid, sizeof(afs_uuid)) == 0)
reply.match = htonl(0);
else
reply.match = htonl(1);
afs_send_simple_reply(call, &reply, sizeof(reply));
_leave("");
}
/*
* deliver request data to a CB.ProbeUuid call
*/
static int afs_deliver_cb_probe_uuid(struct afs_call *call, struct sk_buff *skb,
bool last)
{
struct afs_uuid *r;
unsigned loop;
__be32 *b;
int ret;
_enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
switch (call->unmarshall) {
case 0:
call->offset = 0;
call->buffer = kmalloc(11 * sizeof(__be32), GFP_KERNEL);
if (!call->buffer)
return -ENOMEM;
call->unmarshall++;
case 1:
_debug("extract UUID");
ret = afs_extract_data(call, skb, last, call->buffer,
11 * sizeof(__be32));
switch (ret) {
case 0: break;
case -EAGAIN: return 0;
default: return ret;
}
_debug("unmarshall UUID");
call->request = kmalloc(sizeof(struct afs_uuid), GFP_KERNEL);
if (!call->request)
return -ENOMEM;
b = call->buffer;
r = call->request;
r->time_low = ntohl(b[0]);
r->time_mid = ntohl(b[1]);
r->time_hi_and_version = ntohl(b[2]);
r->clock_seq_hi_and_reserved = ntohl(b[3]);
r->clock_seq_low = ntohl(b[4]);
for (loop = 0; loop < 6; loop++)
r->node[loop] = ntohl(b[loop + 5]);
call->offset = 0;
call->unmarshall++;
case 2:
_debug("trailer");
if (skb->len != 0)
return -EBADMSG;
break;
}
if (!last)
return 0;
call->state = AFS_CALL_REPLYING;
INIT_WORK(&call->work, SRXAFSCB_ProbeUuid);
queue_work(afs_wq, &call->work);
return 0;
}
/*
* allow the fileserver to ask about the cache manager's capabilities
*/
static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
{
struct afs_interface *ifs;
struct afs_call *call = container_of(work, struct afs_call, work);
int loop, nifs;
struct {
struct /* InterfaceAddr */ {
__be32 nifs;
__be32 uuid[11];
__be32 ifaddr[32];
__be32 netmask[32];
__be32 mtu[32];
} ia;
struct /* Capabilities */ {
__be32 capcount;
__be32 caps[1];
} cap;
} reply;
_enter("");
nifs = 0;
ifs = kcalloc(32, sizeof(*ifs), GFP_KERNEL);
if (ifs) {
nifs = afs_get_ipv4_interfaces(ifs, 32, false);
if (nifs < 0) {
kfree(ifs);
ifs = NULL;
nifs = 0;
}
}
memset(&reply, 0, sizeof(reply));
reply.ia.nifs = htonl(nifs);
reply.ia.uuid[0] = htonl(afs_uuid.time_low);
reply.ia.uuid[1] = htonl(afs_uuid.time_mid);
reply.ia.uuid[2] = htonl(afs_uuid.time_hi_and_version);
reply.ia.uuid[3] = htonl((s8) afs_uuid.clock_seq_hi_and_reserved);
reply.ia.uuid[4] = htonl((s8) afs_uuid.clock_seq_low);
for (loop = 0; loop < 6; loop++)
reply.ia.uuid[loop + 5] = htonl((s8) afs_uuid.node[loop]);
if (ifs) {
for (loop = 0; loop < nifs; loop++) {
reply.ia.ifaddr[loop] = ifs[loop].address.s_addr;
reply.ia.netmask[loop] = ifs[loop].netmask.s_addr;
reply.ia.mtu[loop] = htonl(ifs[loop].mtu);
}
kfree(ifs);
}
reply.cap.capcount = htonl(1);
reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION);
afs_send_simple_reply(call, &reply, sizeof(reply));
_leave("");
}
/*
* deliver request data to a CB.TellMeAboutYourself call
*/
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call,
struct sk_buff *skb, bool last)
{
_enter(",{%u},%d", skb->len, last);
if (skb->len > 0)
return -EBADMSG;
if (!last)
return 0;
/* no unmarshalling required */
call->state = AFS_CALL_REPLYING;
INIT_WORK(&call->work, SRXAFSCB_TellMeAboutYourself);
queue_work(afs_wq, &call->work);
return 0;
}
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