Message ID | 1565667334-22071-1-git-send-email-zhengbin13@huawei.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | [v4] SCSI: fix queue cleanup race before scsi_requeue_run_queue is done | expand |
On 8/14/19 6:50 PM, zhengbin (A) wrote:
> ping
Sending a "ping" after 46 hours is way too soon and only causes
irritation. What would help though is more information about how this
patch has been tested. Does it e.g. survive the srp tests in blktests?
Thanks,
Bart.
On 2019/8/15 23:40, Bart Van Assche wrote: > On 8/14/19 6:50 PM, zhengbin (A) wrote: >> ping > > Sending a "ping" after 46 hours is way too soon and only causes irritation. What would help though is more information about how this patch has been tested. Does it e.g. survive the srp tests in blktests? Very sorry for the noise, it won't happen again next time. I have done abnormal operations while running sdtester, it is ok within this patch after a day. Without this, it will cause oops because of use-after-free after about 4 hours. > > Thanks, > > Bart. > > . >
On 8/12/19 8:35 PM, zhengbin wrote: > KASAN reports a use-after-free in 4.19-stable, > which won't happen after commit 47cdee29ef9d > ("block: move blk_exit_queue into __blk_release_queue"). This patch doesn't apply on top of kernel v4.19.67: $ git am ~/\[PATCH\ v4\]\ SCSI\:\ fix\ queue\ cleanup\ race\ before\ scsi_requeue_run_queue\ is\ done.eml Applying: SCSI: fix queue cleanup race before scsi_requeue_run_queue is done error: patch failed: drivers/scsi/scsi_lib.c:531 error: drivers/scsi/scsi_lib.c: patch does not apply Patch failed at 0001 SCSI: fix queue cleanup race before scsi_requeue_run_queue is done $ patch -p1 < ~/\[PATCH\ v4\]\ SCSI\:\ fix\ queue\ cleanup\ race\ before\ scsi_requeue_run_queue\ is\ done.eml (Stripping trailing CRs from patch; use --binary to disable.) patching file drivers/scsi/scsi_lib.c Hunk #1 succeeded at 548 with fuzz 1 (offset 17 lines). Hunk #2 FAILED at 618. 1 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/scsi_lib.c.rej (Stripping trailing CRs from patch; use --binary to disable.) patching file drivers/scsi/scsi_sysfs.c Hunk #1 succeeded at 1392 (offset -18 lines). Bart.
On 2019/8/17 1:09, Bart Van Assche wrote: > On 8/12/19 8:35 PM, zhengbin wrote: >> KASAN reports a use-after-free in 4.19-stable, >> which won't happen after commit 47cdee29ef9d >> ("block: move blk_exit_queue into __blk_release_queue"). > > This patch doesn't apply on top of kernel v4.19.67: > > $ git am ~/\[PATCH\ v4\]\ SCSI\:\ fix\ queue\ cleanup\ race\ before\ scsi_requeue_run_queue\ is\ done.eml > Applying: SCSI: fix queue cleanup race before scsi_requeue_run_queue is done > error: patch failed: drivers/scsi/scsi_lib.c:531 > error: drivers/scsi/scsi_lib.c: patch does not apply > Patch failed at 0001 SCSI: fix queue cleanup race before scsi_requeue_run_queue is done > > $ patch -p1 < ~/\[PATCH\ v4\]\ SCSI\:\ fix\ queue\ cleanup\ race\ before\ scsi_requeue_run_queue\ is\ done.eml > (Stripping trailing CRs from patch; use --binary to disable.) > patching file drivers/scsi/scsi_lib.c > Hunk #1 succeeded at 548 with fuzz 1 (offset 17 lines). > Hunk #2 FAILED at 618. > 1 out of 2 hunks FAILED -- saving rejects to file drivers/scsi/scsi_lib.c.rej > (Stripping trailing CRs from patch; use --binary to disable.) > patching file drivers/scsi/scsi_sysfs.c > Hunk #1 succeeded at 1392 (offset -18 lines). This patch is for master, not for 4.19-stable. In SCSI, master has only blk-mq, while 4.19-stable has blk-sq(single queue) & mq. I will send a patch for 4.19-stable later. > > Bart. > > . >
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 11e64b5..b3503f9 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -531,6 +531,11 @@ void scsi_requeue_run_queue(struct work_struct *work) sdev = container_of(work, struct scsi_device, requeue_work); q = sdev->request_queue; scsi_run_queue(q); + /* + * need to put q_usage_counter which + * is got in scsi_end_request. + */ + percpu_ref_put(&q->q_usage_counter); } void scsi_run_host_queues(struct Scsi_Host *shost) @@ -613,12 +618,14 @@ static bool scsi_end_request(struct request *req, blk_status_t error, __blk_mq_end_request(req, error); if (scsi_target(sdev)->single_lun || - !list_empty(&sdev->host->starved_list)) - kblockd_schedule_work(&sdev->requeue_work); - else + !list_empty(&sdev->host->starved_list)) { + if (!kblockd_schedule_work(&sdev->requeue_work)) + percpu_ref_put(&q->q_usage_counter); + } else { blk_mq_run_hw_queues(q, true); + percpu_ref_put(&q->q_usage_counter); + } - percpu_ref_put(&q->q_usage_counter); return false; } diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 64c96c7..03e3567 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -1410,7 +1410,8 @@ void __scsi_remove_device(struct scsi_device *sdev) mutex_unlock(&sdev->state_mutex); blk_cleanup_queue(sdev->request_queue); - cancel_work_sync(&sdev->requeue_work); + if (cancel_work_sync(&sdev->requeue_work)) + percpu_ref_put(&sdev->request_queue->q_usage_counter); if (sdev->host->hostt->slave_destroy) sdev->host->hostt->slave_destroy(sdev);
KASAN reports a use-after-free in 4.19-stable, which won't happen after commit 47cdee29ef9d ("block: move blk_exit_queue into __blk_release_queue"). However, backport this patch to 4.19-stable will be a lot of work and the risk is great. Moreover, we should make sure scsi_requeue_run_queue is done before blk_cleanup_queue in master too. BUG: KASAN: use-after-free in dd_has_work+0x50/0xe8 Read of size 8 at addr ffff808b57c6f168 by task kworker/53:1H/6910 CPU: 53 PID: 6910 Comm: kworker/53:1H Kdump: loaded Tainted: G Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.59 01/31/2019 Workqueue: kblockd scsi_requeue_run_queue Call trace: dump_backtrace+0x0/0x270 show_stack+0x24/0x30 dump_stack+0xb4/0xe4 print_address_description+0x68/0x278 kasan_report+0x204/0x330 __asan_load8+0x88/0xb0 dd_has_work+0x50/0xe8 blk_mq_run_hw_queue+0x19c/0x218 blk_mq_run_hw_queues+0x7c/0xb0 scsi_run_queue+0x3ec/0x520 scsi_requeue_run_queue+0x2c/0x38 process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Allocated by task 46843: kasan_kmalloc+0xe0/0x190 kmem_cache_alloc_node_trace+0x10c/0x258 dd_init_queue+0x68/0x190 blk_mq_init_sched+0x1cc/0x300 elevator_init_mq+0x90/0xe0 blk_mq_init_allocated_queue+0x700/0x728 blk_mq_init_queue+0x48/0x90 scsi_mq_alloc_queue+0x34/0xb0 scsi_alloc_sdev+0x340/0x530 scsi_probe_and_add_lun+0x46c/0x1260 __scsi_scan_target+0x1b8/0x7b0 scsi_scan_target+0x140/0x150 fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Freed by task 46843: __kasan_slab_free+0x120/0x228 kasan_slab_free+0x10/0x18 kfree+0x88/0x218 dd_exit_queue+0x5c/0x78 blk_mq_exit_sched+0x104/0x130 elevator_exit+0xa8/0xc8 blk_exit_queue+0x48/0x78 blk_cleanup_queue+0x170/0x248 __scsi_remove_device+0x84/0x1b0 scsi_probe_and_add_lun+0xd00/0x1260 __scsi_scan_target+0x1b8/0x7b0 scsi_scan_target+0x140/0x150 fc_scsi_scan_rport+0x164/0x178 [scsi_transport_fc] process_one_work+0x2e4/0x6d8 worker_thread+0x6c/0x6a8 kthread+0x1b4/0x1c0 ret_from_fork+0x10/0x18 Fixes: 8dc765d438f1 ("SCSI: fix queue cleanup race before queue initialization is done") Signed-off-by: zhengbin <zhengbin13@huawei.com> --- drivers/scsi/scsi_lib.c | 15 +++++++++++---- drivers/scsi/scsi_sysfs.c | 3 ++- 2 files changed, 13 insertions(+), 5 deletions(-) -- 2.7.4