1. 28 Feb, 2022 10 commits
  2. 27 Feb, 2022 13 commits
  3. 22 Feb, 2022 1 commit
  4. 18 Feb, 2022 3 commits
    • Yu Kuai's avatar
      block, bfq: don't move oom_bfqq · 8410f709
      Yu Kuai authored
      Our test report a UAF:
      
      [ 2073.019181] ==================================================================
      [ 2073.019188] BUG: KASAN: use-after-free in __bfq_put_async_bfqq+0xa0/0x168
      [ 2073.019191] Write of size 8 at addr ffff8000ccf64128 by task rmmod/72584
      [ 2073.019192]
      [ 2073.019196] CPU: 0 PID: 72584 Comm: rmmod Kdump: loaded Not tainted 4.19.90-yk #5
      [ 2073.019198] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
      [ 2073.019200] Call trace:
      [ 2073.019203]  dump_backtrace+0x0/0x310
      [ 2073.019206]  show_stack+0x28/0x38
      [ 2073.019210]  dump_stack+0xec/0x15c
      [ 2073.019216]  print_address_description+0x68/0x2d0
      [ 2073.019220]  kasan_report+0x238/0x2f0
      [ 2073.019224]  __asan_store8+0x88/0xb0
      [ 2073.019229]  __bfq_put_async_bfqq+0xa0/0x168
      [ 2073.019233]  bfq_put_async_queues+0xbc/0x208
      [ 2073.019236]  bfq_pd_offline+0x178/0x238
      [ 2073.019240]  blkcg_deactivate_policy+0x1f0/0x420
      [ 2073.019244]  bfq_exit_queue+0x128/0x178
      [ 2073.019249]  blk_mq_exit_sched+0x12c/0x160
      [ 2073.019252]  elevator_exit+0xc8/0xd0
      [ 2073.019256]  blk_exit_queue+0x50/0x88
      [ 2073.019259]  blk_cleanup_queue+0x228/0x3d8
      [ 2073.019267]  null_del_dev+0xfc/0x1e0 [null_blk]
      [ 2073.019274]  null_exit+0x90/0x114 [null_blk]
      [ 2073.019278]  __arm64_sys_delete_module+0x358/0x5a0
      [ 2073.019282]  el0_svc_common+0xc8/0x320
      [ 2073.019287]  el0_svc_handler+0xf8/0x160
      [ 2073.019290]  el0_svc+0x10/0x218
      [ 2073.019291]
      [ 2073.019294] Allocated by task 14163:
      [ 2073.019301]  kasan_kmalloc+0xe0/0x190
      [ 2073.019305]  kmem_cache_alloc_node_trace+0x1cc/0x418
      [ 2073.019308]  bfq_pd_alloc+0x54/0x118
      [ 2073.019313]  blkcg_activate_policy+0x250/0x460
      [ 2073.019317]  bfq_create_group_hierarchy+0x38/0x110
      [ 2073.019321]  bfq_init_queue+0x6d0/0x948
      [ 2073.019325]  blk_mq_init_sched+0x1d8/0x390
      [ 2073.019330]  elevator_switch_mq+0x88/0x170
      [ 2073.019334]  elevator_switch+0x140/0x270
      [ 2073.019338]  elv_iosched_store+0x1a4/0x2a0
      [ 2073.019342]  queue_attr_store+0x90/0xe0
      [ 2073.019348]  sysfs_kf_write+0xa8/0xe8
      [ 2073.019351]  kernfs_fop_write+0x1f8/0x378
      [ 2073.019359]  __vfs_write+0xe0/0x360
      [ 2073.019363]  vfs_write+0xf0/0x270
      [ 2073.019367]  ksys_write+0xdc/0x1b8
      [ 2073.019371]  __arm64_sys_write+0x50/0x60
      [ 2073.019375]  el0_svc_common+0xc8/0x320
      [ 2073.019380]  el0_svc_handler+0xf8/0x160
      [ 2073.019383]  el0_svc+0x10/0x218
      [ 2073.019385]
      [ 2073.019387] Freed by task 72584:
      [ 2073.019391]  __kasan_slab_free+0x120/0x228
      [ 2073.019394]  kasan_slab_free+0x10/0x18
      [ 2073.019397]  kfree+0x94/0x368
      [ 2073.019400]  bfqg_put+0x64/0xb0
      [ 2073.019404]  bfqg_and_blkg_put+0x90/0xb0
      [ 2073.019408]  bfq_put_queue+0x220/0x228
      [ 2073.019413]  __bfq_put_async_bfqq+0x98/0x168
      [ 2073.019416]  bfq_put_async_queues+0xbc/0x208
      [ 2073.019420]  bfq_pd_offline+0x178/0x238
      [ 2073.019424]  blkcg_deactivate_policy+0x1f0/0x420
      [ 2073.019429]  bfq_exit_queue+0x128/0x178
      [ 2073.019433]  blk_mq_exit_sched+0x12c/0x160
      [ 2073.019437]  elevator_exit+0xc8/0xd0
      [ 2073.019440]  blk_exit_queue+0x50/0x88
      [ 2073.019443]  blk_cleanup_queue+0x228/0x3d8
      [ 2073.019451]  null_del_dev+0xfc/0x1e0 [null_blk]
      [ 2073.019459]  null_exit+0x90/0x114 [null_blk]
      [ 2073.019462]  __arm64_sys_delete_module+0x358/0x5a0
      [ 2073.019467]  el0_svc_common+0xc8/0x320
      [ 2073.019471]  el0_svc_handler+0xf8/0x160
      [ 2073.019474]  el0_svc+0x10/0x218
      [ 2073.019475]
      [ 2073.019479] The buggy address belongs to the object at ffff8000ccf63f00
       which belongs to the cache kmalloc-1024 of size 1024
      [ 2073.019484] The buggy address is located 552 bytes inside of
       1024-byte region [ffff8000ccf63f00, ffff8000ccf64300)
      [ 2073.019486] The buggy address belongs to the page:
      [ 2073.019492] page:ffff7e000333d800 count:1 mapcount:0 mapping:ffff8000c0003a00 index:0x0 compound_mapcount: 0
      [ 2073.020123] flags: 0x7ffff0000008100(slab|head)
      [ 2073.020403] raw: 07ffff0000008100 ffff7e0003334c08 ffff7e00001f5a08 ffff8000c0003a00
      [ 2073.020409] raw: 0000000000000000 00000000001c001c 00000001ffffffff 0000000000000000
      [ 2073.020411] page dumped because: kasan: bad access detected
      [ 2073.020412]
      [ 2073.020414] Memory state around the buggy address:
      [ 2073.020420]  ffff8000ccf64000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [ 2073.020424]  ffff8000ccf64080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [ 2073.020428] >ffff8000ccf64100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [ 2073.020430]                                   ^
      [ 2073.020434]  ffff8000ccf64180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [ 2073.020438]  ffff8000ccf64200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      [ 2073.020439] ==================================================================
      
      The same problem exist in mainline as well.
      
      This is because oom_bfqq is moved to a non-root group, thus root_group
      is freed earlier.
      
      Thus fix the problem by don't move oom_bfqq.
      Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Acked-by: default avatarPaolo Valente <paolo.valente@linaro.org>
      Link: https://lore.kernel.org/r/20220129015924.3958918-4-yukuai3@huawei.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      8410f709
    • Yu Kuai's avatar
      block, bfq: avoid moving bfqq to it's parent bfqg · c5e4cb0f
      Yu Kuai authored
      Moving bfqq to it's parent bfqg is pointless.
      Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
      Link: https://lore.kernel.org/r/20220129015924.3958918-3-yukuai3@huawei.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      c5e4cb0f
    • Yu Kuai's avatar
      block, bfq: cleanup bfq_bfqq_to_bfqg() · 43a4b1fe
      Yu Kuai authored
      Use bfq_group() instead, which do the same thing.
      Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Acked-by: default avatarPaolo Valente <paolo.valente@linaro.org>
      Link: https://lore.kernel.org/r/20220129015924.3958918-2-yukuai3@huawei.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      43a4b1fe
  5. 17 Feb, 2022 13 commits