From: Yu Kuai <yukuai3@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I58VDJ CVE: NA -------------------------------- Our test report a crash: run fstests generic/349 at 2022-05-20 20:55:10 sd 3:0:0:0: Power-on or device reset occurred BUG: kernel NULL pointer dereference, address: 0000000000000030 Call Trace: disk_release+0x42/0x170 device_release+0x92/0x120 kobject_put+0x183/0x350 put_disk+0x23/0x30 sg_device_destroy+0x77/0xd0 sg_remove_device+0x1b8/0x220 device_del+0x19b/0x610 ? kfree_const+0x3e/0x50 ? kobject_put+0x1d1/0x350 device_unregister+0x36/0xa0 __scsi_remove_device+0x1ba/0x240 scsi_forget_host+0x95/0xd0 scsi_remove_host+0xba/0x1f0 sdebug_driver_remove+0x30/0x110 [scsi_debug] device_release_driver_internal+0x1ab/0x340 device_release_driver+0x16/0x20 bus_remove_device+0x167/0x220 device_del+0x23e/0x610 device_unregister+0x36/0xa0 sdebug_do_remove_host+0x159/0x190 [scsi_debug] scsi_debug_exit+0x2d/0x120 [scsi_debug] __se_sys_delete_module+0x34c/0x420 ? exit_to_user_mode_prepare+0x93/0x210 __x64_sys_delete_module+0x1a/0x30 do_syscall_64+0x4d/0x70 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Such crash happened since commit 2a19b28f7929 ("blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()") was backported from mainline. commit 61a35cfc2633 ("block: hold a request_queue reference for the lifetime of struct gendisk") is not backported, thus we can't ensure request_queue still exist in disk_release(), and that's why blk_mq_cancel_work_sync() will triggered the problem in disk_release(). However, in order to backport it, there are too many relied patches and kabi will be broken. Since we didn't backport related patches to tear down file system I/O in del_gendisk, which fix issues introduced by refactor patches to move bdi from request_queue to the disk, there is no need to call blk_mq_cancel_work_sync() from disk_release(). This patch just remove blk_mq_cancel_work_sync() from disk_release() to fix the above crash. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- block/genhd.c | 1 - 1 file changed, 1 deletion(-) diff --git a/block/genhd.c b/block/genhd.c index 5b6cd992c6a6..f94152e99876 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1572,7 +1572,6 @@ static void disk_release(struct device *dev) might_sleep(); blk_free_devt(dev->devt); - blk_mq_cancel_work_sync(disk->queue); disk_release_events(disk); kfree(disk->random); disk_replace_part_tbl(disk, NULL); -- 2.20.1