Laibin Qiu 1d61255327 blkcg: Remove extra blkcg_bio_issue_init
[ Upstream commit b781d8db580c058ecd54ed7d5dde7f8270b25f5b ]

KASAN reports a use-after-free report when doing block test:

==================================================================
[10050.967049] BUG: KASAN: use-after-free in
submit_bio_checks+0x1539/0x1550

[10050.977638] Call Trace:
[10050.978190]  dump_stack+0x9b/0xce
[10050.979674]  print_address_description.constprop.6+0x3e/0x60
[10050.983510]  kasan_report.cold.9+0x22/0x3a
[10050.986089]  submit_bio_checks+0x1539/0x1550
[10050.989576]  submit_bio_noacct+0x83/0xc80
[10050.993714]  submit_bio+0xa7/0x330
[10050.994435]  mpage_readahead+0x380/0x500
[10050.998009]  read_pages+0x1c1/0xbf0
[10051.002057]  page_cache_ra_unbounded+0x4c2/0x6f0
[10051.007413]  do_page_cache_ra+0xda/0x110
[10051.008207]  force_page_cache_ra+0x23d/0x3d0
[10051.009087]  page_cache_sync_ra+0xca/0x300
[10051.009970]  generic_file_buffered_read+0xbea/0x2130
[10051.012685]  generic_file_read_iter+0x315/0x490
[10051.014472]  blkdev_read_iter+0x113/0x1b0
[10051.015300]  aio_read+0x2ad/0x450
[10051.023786]  io_submit_one+0xc8e/0x1d60
[10051.029855]  __se_sys_io_submit+0x125/0x350
[10051.033442]  do_syscall_64+0x2d/0x40
[10051.034156]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[10051.048733] Allocated by task 18598:
[10051.049482]  kasan_save_stack+0x19/0x40
[10051.050263]  __kasan_kmalloc.constprop.1+0xc1/0xd0
[10051.051230]  kmem_cache_alloc+0x146/0x440
[10051.052060]  mempool_alloc+0x125/0x2f0
[10051.052818]  bio_alloc_bioset+0x353/0x590
[10051.053658]  mpage_alloc+0x3b/0x240
[10051.054382]  do_mpage_readpage+0xddf/0x1ef0
[10051.055250]  mpage_readahead+0x264/0x500
[10051.056060]  read_pages+0x1c1/0xbf0
[10051.056758]  page_cache_ra_unbounded+0x4c2/0x6f0
[10051.057702]  do_page_cache_ra+0xda/0x110
[10051.058511]  force_page_cache_ra+0x23d/0x3d0
[10051.059373]  page_cache_sync_ra+0xca/0x300
[10051.060198]  generic_file_buffered_read+0xbea/0x2130
[10051.061195]  generic_file_read_iter+0x315/0x490
[10051.062189]  blkdev_read_iter+0x113/0x1b0
[10051.063015]  aio_read+0x2ad/0x450
[10051.063686]  io_submit_one+0xc8e/0x1d60
[10051.064467]  __se_sys_io_submit+0x125/0x350
[10051.065318]  do_syscall_64+0x2d/0x40
[10051.066082]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[10051.067455] Freed by task 13307:
[10051.068136]  kasan_save_stack+0x19/0x40
[10051.068931]  kasan_set_track+0x1c/0x30
[10051.069726]  kasan_set_free_info+0x1b/0x30
[10051.070621]  __kasan_slab_free+0x111/0x160
[10051.071480]  kmem_cache_free+0x94/0x460
[10051.072256]  mempool_free+0xd6/0x320
[10051.072985]  bio_free+0xe0/0x130
[10051.073630]  bio_put+0xab/0xe0
[10051.074252]  bio_endio+0x3a6/0x5d0
[10051.074984]  blk_update_request+0x590/0x1370
[10051.075870]  scsi_end_request+0x7d/0x400
[10051.076667]  scsi_io_completion+0x1aa/0xe50
[10051.077503]  scsi_softirq_done+0x11b/0x240
[10051.078344]  blk_mq_complete_request+0xd4/0x120
[10051.079275]  scsi_mq_done+0xf0/0x200
[10051.080036]  virtscsi_vq_done+0xbc/0x150
[10051.080850]  vring_interrupt+0x179/0x390
[10051.081650]  __handle_irq_event_percpu+0xf7/0x490
[10051.082626]  handle_irq_event_percpu+0x7b/0x160
[10051.083527]  handle_irq_event+0xcc/0x170
[10051.084297]  handle_edge_irq+0x215/0xb20
[10051.085122]  asm_call_irq_on_stack+0xf/0x20
[10051.085986]  common_interrupt+0xae/0x120
[10051.086830]  asm_common_interrupt+0x1e/0x40

==================================================================

Bio will be checked at beginning of submit_bio_noacct(). If bio needs
to be throttled, it will start the timer and stop submit bio directly.
Bio will submit in blk_throtl_dispatch_work_fn() when the timer expires.
But in the current process, if bio is throttled, it will still set bio
issue->value by blkcg_bio_issue_init(). This is redundant and may cause
the above use-after-free.

CPU0                                   CPU1
submit_bio
submit_bio_noacct
  submit_bio_checks
    blk_throtl_bio()
      <=mod_timer(&sq->pending_timer
                                      blk_throtl_dispatch_work_fn
                                        submit_bio_noacct() <= bio have
                                        throttle tag, will throw directly
                                        and bio issue->value will be set
                                        here

                                      bio_endio()
                                      bio_put()
                                      bio_free() <= free this bio

    blkcg_bio_issue_init(bio)
      <= bio has been freed and
      will lead to UAF
  return BLK_QC_T_NONE

Fix this by remove extra blkcg_bio_issue_init.

Fixes: e439bedf6b24 (blkcg: consolidate bio_issue_init() to be a part of core)
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Link: https://lore.kernel.org/r/20211112093354.3581504-1-qiulaibin@huawei.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-26 10:39:13 +01:00
2020-10-17 11:18:18 -07:00
2021-11-21 13:46:37 +01:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%