Yu Kuai
3802f73bd8
block: fix uaf for flush rq while iterating tags
blk_mq_clear_flush_rq_mapping() is not called during scsi probe, by
checking blk_queue_init_done(). However, QUEUE_FLAG_INIT_DONE is cleared
in del_gendisk by commit aec89dc5d4 ("block: keep q_usage_counter in
atomic mode after del_gendisk"), hence for disk like scsi, following
blk_mq_destroy_queue() will not clear flush rq from tags->rqs[] as well,
cause following uaf that is found by our syzkaller for v6.6:
==================================================================
BUG: KASAN: slab-use-after-free in blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261
Read of size 4 at addr ffff88811c969c20 by task kworker/1:2H/224909
CPU: 1 PID: 224909 Comm: kworker/1:2H Not tainted 6.6.0-ga836a5060850 #32
Workqueue: kblockd blk_mq_timeout_work
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106
print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364
print_report+0x3e/0x70 mm/kasan/report.c:475
kasan_report+0xb8/0xf0 mm/kasan/report.c:588
blk_mq_find_and_get_req+0x16e/0x1a0 block/blk-mq-tag.c:261
bt_iter block/blk-mq-tag.c:288 [inline]
__sbitmap_for_each_set include/linux/sbitmap.h:295 [inline]
sbitmap_for_each_set include/linux/sbitmap.h:316 [inline]
bt_for_each+0x455/0x790 block/blk-mq-tag.c:325
blk_mq_queue_tag_busy_iter+0x320/0x740 block/blk-mq-tag.c:534
blk_mq_timeout_work+0x1a3/0x7b0 block/blk-mq.c:1673
process_one_work+0x7c4/0x1450 kernel/workqueue.c:2631
process_scheduled_works kernel/workqueue.c:2704 [inline]
worker_thread+0x804/0xe40 kernel/workqueue.c:2785
kthread+0x346/0x450 kernel/kthread.c:388
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:293
Allocated by task 942:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc mm/kasan/common.c:383 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:380
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node+0x69/0x170 mm/slab_common.c:1014
kmalloc_node include/linux/slab.h:620 [inline]
kzalloc_node include/linux/slab.h:732 [inline]
blk_alloc_flush_queue+0x144/0x2f0 block/blk-flush.c:499
blk_mq_alloc_hctx+0x601/0x940 block/blk-mq.c:3788
blk_mq_alloc_and_init_hctx+0x27f/0x330 block/blk-mq.c:4261
blk_mq_realloc_hw_ctxs+0x488/0x5e0 block/blk-mq.c:4294
blk_mq_init_allocated_queue+0x188/0x860 block/blk-mq.c:4350
blk_mq_init_queue_data block/blk-mq.c:4166 [inline]
blk_mq_init_queue+0x8d/0x100 block/blk-mq.c:4176
scsi_alloc_sdev+0x843/0xd50 drivers/scsi/scsi_scan.c:335
scsi_probe_and_add_lun+0x77c/0xde0 drivers/scsi/scsi_scan.c:1189
__scsi_scan_target+0x1fc/0x5a0 drivers/scsi/scsi_scan.c:1727
scsi_scan_channel drivers/scsi/scsi_scan.c:1815 [inline]
scsi_scan_channel+0x14b/0x1e0 drivers/scsi/scsi_scan.c:1791
scsi_scan_host_selected+0x2fe/0x400 drivers/scsi/scsi_scan.c:1844
scsi_scan+0x3a0/0x3f0 drivers/scsi/scsi_sysfs.c:151
store_scan+0x2a/0x60 drivers/scsi/scsi_sysfs.c:191
dev_attr_store+0x5c/0x90 drivers/base/core.c:2388
sysfs_kf_write+0x11c/0x170 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x3fc/0x610 fs/kernfs/file.c:338
call_write_iter include/linux/fs.h:2083 [inline]
new_sync_write+0x1b4/0x2d0 fs/read_write.c:493
vfs_write+0x76c/0xb00 fs/read_write.c:586
ksys_write+0x127/0x250 fs/read_write.c:639
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x78/0xe2
Freed by task 244687:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x50 mm/kasan/generic.c:522
____kasan_slab_free mm/kasan/common.c:236 [inline]
__kasan_slab_free+0x12a/0x1b0 mm/kasan/common.c:244
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1815 [inline]
slab_free_freelist_hook mm/slub.c:1841 [inline]
slab_free mm/slub.c:3807 [inline]
__kmem_cache_free+0xe4/0x520 mm/slub.c:3820
blk_free_flush_queue+0x40/0x60 block/blk-flush.c:520
blk_mq_hw_sysfs_release+0x4a/0x170 block/blk-mq-sysfs.c:37
kobject_cleanup+0x136/0x410 lib/kobject.c:689
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x119/0x140 lib/kobject.c:737
blk_mq_release+0x24f/0x3f0 block/blk-mq.c:4144
blk_free_queue block/blk-core.c:298 [inline]
blk_put_queue+0xe2/0x180 block/blk-core.c:314
blkg_free_workfn+0x376/0x6e0 block/blk-cgroup.c:144
process_one_work+0x7c4/0x1450 kernel/workqueue.c:2631
process_scheduled_works kernel/workqueue.c:2704 [inline]
worker_thread+0x804/0xe40 kernel/workqueue.c:2785
kthread+0x346/0x450 kernel/kthread.c:388
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:293
Other than blk_mq_clear_flush_rq_mapping(), the flag is only used in
blk_register_queue() from initialization path, hence it's safe not to
clear the flag in del_gendisk. And since QUEUE_FLAG_REGISTERED already
make sure that queue should only be registered once, there is no need
to test the flag as well.
Fixes: 6cfeadbff3 ("blk-mq: don't clear flush_rq from tags->rqs[]")
Depends-on: commit aec89dc5d4 ("block: keep q_usage_counter in atomic mode after del_gendisk")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241104110005.1412161-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-18 18:31:57 -07:00
..
2024-10-22 08:15:17 -06:00
2023-12-23 18:38:08 -07:00
2024-09-25 14:56:40 -07:00
2024-09-10 16:32:09 -06:00
2024-09-10 16:32:09 -06:00
2024-09-10 16:32:09 -06:00
2023-01-29 15:18:33 -07:00
2024-10-30 07:49:32 -06:00
2024-11-11 08:35:46 -07:00
2023-06-01 09:13:31 -06:00
2024-04-03 09:10:17 -06:00
2022-07-14 12:14:30 -06:00
2024-07-28 16:47:51 -06:00
2024-08-16 15:07:27 -06:00
2024-11-13 12:04:58 -07:00
2024-11-11 08:35:46 -07:00
2023-03-16 09:35:09 -06:00
2023-07-05 16:36:12 -06:00
2023-02-09 09:38:16 -07:00
2023-03-16 09:35:09 -06:00
2024-07-15 14:20:22 -07:00
2023-02-09 09:38:16 -07:00
2024-10-30 07:49:32 -06:00
2024-10-22 08:16:40 -06:00
2024-10-02 07:15:43 -06:00
2024-02-05 10:07:22 -07:00
2024-07-28 16:47:51 -06:00
2024-07-28 16:47:51 -06:00
2024-08-28 08:49:25 -06:00
2024-07-03 10:21:16 -06:00
2024-11-13 12:04:58 -07:00
2023-04-13 06:52:29 -06:00
2024-07-19 09:32:49 -06:00
2024-04-17 08:44:03 -06:00
2023-04-13 06:52:29 -06:00
2024-01-17 14:16:34 -07:00
2023-05-18 19:42:54 -06:00
2023-04-13 06:52:29 -06:00
2024-08-15 19:25:03 -06:00
2023-04-13 06:52:29 -06:00
2024-11-13 12:04:58 -07:00
2024-11-13 12:04:58 -07:00
2023-11-20 10:22:40 -07:00
2021-02-22 06:33:48 -07:00
2024-10-22 14:05:09 -06:00
2023-12-01 18:29:18 -07:00
2024-11-18 14:54:50 -07:00
2024-05-09 09:44:55 -06:00
2024-05-27 13:58:06 -06:00
2024-11-18 18:31:57 -07:00
2024-10-22 08:16:43 -06:00
2024-09-10 16:31:41 -06:00
2024-07-01 06:51:53 -06:00
2023-12-26 09:28:10 -07:00
2024-11-07 15:30:54 -07:00
2024-11-11 09:06:45 -07:00
2024-07-03 10:21:15 -06:00
2024-05-30 20:22:15 -04:00
2023-06-30 11:57:07 -07:00
2023-10-28 13:29:23 +02:00
2024-05-02 17:48:09 -04:00
2024-11-07 16:27:22 -07:00
2024-10-22 08:16:22 -06:00
2024-10-19 16:48:22 -06:00
2024-11-18 18:31:57 -07:00
2024-02-23 07:44:19 -07:00
2024-09-11 10:45:28 -06:00
2024-01-08 12:27:39 -07:00
2024-06-14 10:20:06 -06:00
2023-01-30 09:42:42 -07:00
2023-04-13 06:52:30 -06:00
2024-06-14 10:20:06 -06:00
2024-07-02 08:47:45 -06:00
2024-02-16 15:52:45 -07:00
2024-10-22 08:16:40 -06:00
2024-10-02 17:23:23 -04:00