Revision 32db864d33c21fd70a217ba53cb7224889354ffb authored by Nikolay Aleksandrov on 30 August 2017, 09:48:59 UTC, committed by David S. Miller on 30 August 2017, 22:26:11 UTC
If sch_hhf fails in its ->init() function (either due to wrong user-space arguments as below or memory alloc failure of hh_flows) it will do a null pointer deref of q->hh_flows in its ->destroy() function. To reproduce the crash: $ tc qdisc add dev eth0 root hhf quantum 2000000 non_hh_weight 10000000 Crash log: [ 690.654882] BUG: unable to handle kernel NULL pointer dereference at (null) [ 690.655565] IP: hhf_destroy+0x48/0xbc [ 690.655944] PGD 37345067 [ 690.655948] P4D 37345067 [ 690.656252] PUD 58402067 [ 690.656554] PMD 0 [ 690.656857] [ 690.657362] Oops: 0000 [#1] SMP [ 690.657696] Modules linked in: [ 690.658032] CPU: 3 PID: 920 Comm: tc Not tainted 4.13.0-rc6+ #57 [ 690.658525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 690.659255] task: ffff880058578000 task.stack: ffff88005acbc000 [ 690.659747] RIP: 0010:hhf_destroy+0x48/0xbc [ 690.660146] RSP: 0018:ffff88005acbf9e0 EFLAGS: 00010246 [ 690.660601] RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000000 [ 690.661155] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff821f63f0 [ 690.661710] RBP: ffff88005acbfa08 R08: ffffffff81b10a90 R09: 0000000000000000 [ 690.662267] R10: 00000000f42b7019 R11: ffff880058578000 R12: 00000000ffffffea [ 690.662820] R13: ffff8800372f6400 R14: 0000000000000000 R15: 0000000000000000 [ 690.663769] FS: 00007f8ae5e8b740(0000) GS:ffff88005d980000(0000) knlGS:0000000000000000 [ 690.667069] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 690.667965] CR2: 0000000000000000 CR3: 0000000058523000 CR4: 00000000000406e0 [ 690.668918] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 690.669945] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 690.671003] Call Trace: [ 690.671743] qdisc_create+0x377/0x3fd [ 690.672534] tc_modify_qdisc+0x4d2/0x4fd [ 690.673324] rtnetlink_rcv_msg+0x188/0x197 [ 690.674204] ? rcu_read_unlock+0x3e/0x5f [ 690.675091] ? rtnl_newlink+0x729/0x729 [ 690.675877] netlink_rcv_skb+0x6c/0xce [ 690.676648] rtnetlink_rcv+0x23/0x2a [ 690.677405] netlink_unicast+0x103/0x181 [ 690.678179] netlink_sendmsg+0x326/0x337 [ 690.678958] sock_sendmsg_nosec+0x14/0x3f [ 690.679743] sock_sendmsg+0x29/0x2e [ 690.680506] ___sys_sendmsg+0x209/0x28b [ 690.681283] ? __handle_mm_fault+0xc7d/0xdb1 [ 690.681915] ? check_chain_key+0xb0/0xfd [ 690.682449] __sys_sendmsg+0x45/0x63 [ 690.682954] ? __sys_sendmsg+0x45/0x63 [ 690.683471] SyS_sendmsg+0x19/0x1b [ 690.683974] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 690.684516] RIP: 0033:0x7f8ae529d690 [ 690.685016] RSP: 002b:00007fff26d2d6b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 690.685931] RAX: ffffffffffffffda RBX: ffffffff810d278c RCX: 00007f8ae529d690 [ 690.686573] RDX: 0000000000000000 RSI: 00007fff26d2d700 RDI: 0000000000000003 [ 690.687047] RBP: ffff88005acbff98 R08: 0000000000000001 R09: 0000000000000000 [ 690.687519] R10: 00007fff26d2d480 R11: 0000000000000246 R12: 0000000000000002 [ 690.687996] R13: 0000000001258070 R14: 0000000000000001 R15: 0000000000000000 [ 690.688475] ? trace_hardirqs_off_caller+0xa7/0xcf [ 690.688887] Code: 00 00 e8 2a 02 ae ff 49 8b bc 1d 60 02 00 00 48 83 c3 08 e8 19 02 ae ff 48 83 fb 20 75 dc 45 31 f6 4d 89 f7 4d 03 bd 20 02 00 00 <49> 8b 07 49 39 c7 75 24 49 83 c6 10 49 81 fe 00 40 00 00 75 e1 [ 690.690200] RIP: hhf_destroy+0x48/0xbc RSP: ffff88005acbf9e0 [ 690.690636] CR2: 0000000000000000 Fixes: 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent e89d469
bsg-lib.c
/*
* BSG helper library
*
* Copyright (C) 2008 James Smart, Emulex Corporation
* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
* Copyright (C) 2011 Mike Christie
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/scatterlist.h>
#include <linux/bsg-lib.h>
#include <linux/export.h>
#include <scsi/scsi_cmnd.h>
/**
* bsg_destroy_job - routine to teardown/delete a bsg job
* @job: bsg_job that is to be torn down
*/
static void bsg_destroy_job(struct kref *kref)
{
struct bsg_job *job = container_of(kref, struct bsg_job, kref);
struct request *rq = job->req;
blk_end_request_all(rq, BLK_STS_OK);
put_device(job->dev); /* release reference for the request */
kfree(job->request_payload.sg_list);
kfree(job->reply_payload.sg_list);
kfree(job);
}
void bsg_job_put(struct bsg_job *job)
{
kref_put(&job->kref, bsg_destroy_job);
}
EXPORT_SYMBOL_GPL(bsg_job_put);
int bsg_job_get(struct bsg_job *job)
{
return kref_get_unless_zero(&job->kref);
}
EXPORT_SYMBOL_GPL(bsg_job_get);
/**
* bsg_job_done - completion routine for bsg requests
* @job: bsg_job that is complete
* @result: job reply result
* @reply_payload_rcv_len: length of payload recvd
*
* The LLD should call this when the bsg job has completed.
*/
void bsg_job_done(struct bsg_job *job, int result,
unsigned int reply_payload_rcv_len)
{
struct request *req = job->req;
struct request *rsp = req->next_rq;
struct scsi_request *rq = scsi_req(req);
int err;
err = scsi_req(job->req)->result = result;
if (err < 0)
/* we're only returning the result field in the reply */
rq->sense_len = sizeof(u32);
else
rq->sense_len = job->reply_len;
/* we assume all request payload was transferred, residual == 0 */
rq->resid_len = 0;
if (rsp) {
WARN_ON(reply_payload_rcv_len > scsi_req(rsp)->resid_len);
/* set reply (bidi) residual */
scsi_req(rsp)->resid_len -=
min(reply_payload_rcv_len, scsi_req(rsp)->resid_len);
}
blk_complete_request(req);
}
EXPORT_SYMBOL_GPL(bsg_job_done);
/**
* bsg_softirq_done - softirq done routine for destroying the bsg requests
* @rq: BSG request that holds the job to be destroyed
*/
static void bsg_softirq_done(struct request *rq)
{
struct bsg_job *job = rq->special;
bsg_job_put(job);
}
static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
{
size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
BUG_ON(!req->nr_phys_segments);
buf->sg_list = kzalloc(sz, GFP_KERNEL);
if (!buf->sg_list)
return -ENOMEM;
sg_init_table(buf->sg_list, req->nr_phys_segments);
scsi_req(req)->resid_len = blk_rq_bytes(req);
buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
buf->payload_len = blk_rq_bytes(req);
return 0;
}
/**
* bsg_create_job - create the bsg_job structure for the bsg request
* @dev: device that is being sent the bsg request
* @req: BSG request that needs a job structure
*/
static int bsg_create_job(struct device *dev, struct request *req)
{
struct request *rsp = req->next_rq;
struct request_queue *q = req->q;
struct scsi_request *rq = scsi_req(req);
struct bsg_job *job;
int ret;
BUG_ON(req->special);
job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);
if (!job)
return -ENOMEM;
req->special = job;
job->req = req;
if (q->bsg_job_size)
job->dd_data = (void *)&job[1];
job->request = rq->cmd;
job->request_len = rq->cmd_len;
job->reply = rq->sense;
job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
* allocated */
if (req->bio) {
ret = bsg_map_buffer(&job->request_payload, req);
if (ret)
goto failjob_rls_job;
}
if (rsp && rsp->bio) {
ret = bsg_map_buffer(&job->reply_payload, rsp);
if (ret)
goto failjob_rls_rqst_payload;
}
job->dev = dev;
/* take a reference for the request */
get_device(job->dev);
kref_init(&job->kref);
return 0;
failjob_rls_rqst_payload:
kfree(job->request_payload.sg_list);
failjob_rls_job:
kfree(job);
return -ENOMEM;
}
/**
* bsg_request_fn - generic handler for bsg requests
* @q: request queue to manage
*
* On error the create_bsg_job function should return a -Exyz error value
* that will be set to ->result.
*
* Drivers/subsys should pass this to the queue init function.
*/
static void bsg_request_fn(struct request_queue *q)
__releases(q->queue_lock)
__acquires(q->queue_lock)
{
struct device *dev = q->queuedata;
struct request *req;
struct bsg_job *job;
int ret;
if (!get_device(dev))
return;
while (1) {
req = blk_fetch_request(q);
if (!req)
break;
spin_unlock_irq(q->queue_lock);
ret = bsg_create_job(dev, req);
if (ret) {
scsi_req(req)->result = ret;
blk_end_request_all(req, BLK_STS_OK);
spin_lock_irq(q->queue_lock);
continue;
}
job = req->special;
ret = q->bsg_job_fn(job);
spin_lock_irq(q->queue_lock);
if (ret)
break;
}
spin_unlock_irq(q->queue_lock);
put_device(dev);
spin_lock_irq(q->queue_lock);
}
/**
* bsg_setup_queue - Create and add the bsg hooks so we can receive requests
* @dev: device to attach bsg device to
* @name: device to give bsg device
* @job_fn: bsg job handler
* @dd_job_size: size of LLD data needed for each job
*/
struct request_queue *bsg_setup_queue(struct device *dev, char *name,
bsg_job_fn *job_fn, int dd_job_size)
{
struct request_queue *q;
int ret;
q = blk_alloc_queue(GFP_KERNEL);
if (!q)
return ERR_PTR(-ENOMEM);
q->cmd_size = sizeof(struct scsi_request);
q->request_fn = bsg_request_fn;
ret = blk_init_allocated_queue(q);
if (ret)
goto out_cleanup_queue;
q->queuedata = dev;
q->bsg_job_size = dd_job_size;
q->bsg_job_fn = job_fn;
queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
blk_queue_softirq_done(q, bsg_softirq_done);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
ret = bsg_register_queue(q, dev, name, NULL);
if (ret) {
printk(KERN_ERR "%s: bsg interface failed to "
"initialize - register queue\n", dev->kobj.name);
goto out_cleanup_queue;
}
return q;
out_cleanup_queue:
blk_cleanup_queue(q);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(bsg_setup_queue);
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