[syzbot] KASAN: use-after-free Write in io_queue_worker_create

syzbot
2021-12-06T06:43:27Z

Hello,

syzbot found the following issue on:

HEAD commit: 944207047ca4 Merge tag 'usb-5.16-rc4' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ebd129b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=171728a464c05f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=b60c982cb0efc5e05a47
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b60c982cb0efc5e05a47@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_write include/linux/instrumented.h:86 [inline]
BUG: KASAN: use-after-free in clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
BUG: KASAN: use-after-free in io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
Write of size 8 at addr ffff888023e068d8 by task kworker/3:4/13798

CPU: 3 PID: 13798 Comm: kworker/3:4 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: events io_workqueue_create
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0x8d/0x2ed mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_write include/linux/instrumented.h:86 [inline]
clear_bit_unlock include/asm-generic/bitops/instrumented-lock.h:25 [inline]
io_queue_worker_create+0x453/0x4e0 fs/io-wq.c:363
io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>

Allocated by task 5554:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
____kasan_kmalloc mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522
kasan_kmalloc include/linux/kasan.h:269 [inline]
kmem_cache_alloc_node_trace+0x208/0x5b0 mm/slab.c:3619
kmalloc_node include/linux/slab.h:608 [inline]
kzalloc_node include/linux/slab.h:735 [inline]
create_io_worker+0x108/0x630 fs/io-wq.c:792
io_wqe_create_worker fs/io-wq.c:300 [inline]
io_wqe_enqueue+0x692/0xbc0 fs/io-wq.c:924
io_queue_async_work+0x28b/0x5d0 fs/io_uring.c:1585
io_queue_sqe_arm_apoll+0xcf/0x1a0 fs/io_uring.c:7004
__io_queue_sqe fs/io_uring.c:7033 [inline]
io_queue_sqe fs/io_uring.c:7060 [inline]
io_submit_sqe fs/io_uring.c:7263 [inline]
io_submit_sqes+0x796a/0x8a20 fs/io_uring.c:7369
__do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10070
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 5554:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xd1/0x110 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
__cache_free mm/slab.c:3445 [inline]
kfree+0x10d/0x2c0 mm/slab.c:3802
create_worker_cont+0x3fb/0x550 fs/io-wq.c:766
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_signal include/linux/tracehook.h:214 [inline]
handle_signal_work kernel/entry/common.c:146 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae

Last potentially related work creation:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
__kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348
task_work_add+0x3a/0x190 kernel/task_work.c:38
io_queue_worker_create+0x3ee/0x4e0 fs/io-wq.c:362
io_workqueue_create+0x9e/0xe0 fs/io-wq.c:780
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Second to last potentially related work creation:
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
__kasan_record_aux_stack+0xb5/0xe0 mm/kasan/generic.c:348
insert_work+0x48/0x370 kernel/workqueue.c:1354
__queue_work+0x5ca/0xee0 kernel/workqueue.c:1520
queue_work_on+0xee/0x110 kernel/workqueue.c:1547
queue_work include/linux/workqueue.h:502 [inline]
schedule_work include/linux/workqueue.h:563 [inline]
create_worker_cont+0x44b/0x550 fs/io-wq.c:772
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_signal include/linux/tracehook.h:214 [inline]
handle_signal_work kernel/entry/common.c:146 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888023e06800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 216 bytes inside of
512-byte region [ffff888023e06800, ffff888023e06a00)
The buggy address belongs to the page:
page:ffffea00008f8180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23e06
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00004f9bc8 ffffea000072de48 ffff888010c40600
raw: 0000000000000000 ffff888023e06000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2c2220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_THISNODE), pid 10854, ts 2474866807743, free_ts 2469053292495
prep_new_page mm/page_alloc.c:2418 [inline]
get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
__alloc_pages_slowpath.constprop.0+0x2eb/0x20d0 mm/page_alloc.c:4914
__alloc_pages+0x412/0x500 mm/page_alloc.c:5382
__alloc_pages_node include/linux/gfp.h:570 [inline]
kmem_getpages mm/slab.c:1377 [inline]
cache_grow_begin+0x75/0x470 mm/slab.c:2593
cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
____cache_alloc mm/slab.c:3048 [inline]
____cache_alloc mm/slab.c:3031 [inline]
slab_alloc_node mm/slab.c:3249 [inline]
kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3617
__do_kmalloc_node mm/slab.c:3639 [inline]
__kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0xde/0x340 net/core/skbuff.c:426
skb_copy+0x137/0x2f0 net/core/skbuff.c:1586
mac80211_hwsim_tx_frame_no_nl.isra.0+0xb17/0x1330 drivers/net/wireless/mac80211_hwsim.c:1565
mac80211_hwsim_tx+0x574/0x12e0 drivers/net/wireless/mac80211_hwsim.c:1669
drv_tx net/mac80211/driver-ops.h:35 [inline]
ieee80211_tx_frags+0x552/0x970 net/mac80211/tx.c:1714
__ieee80211_tx+0x145/0x4c0 net/mac80211/tx.c:1768
ieee80211_tx+0x325/0x420 net/mac80211/tx.c:1948
ieee80211_xmit+0x339/0x420 net/mac80211/tx.c:2040
__ieee80211_subif_start_xmit+0x7ce/0xdc0 net/mac80211/tx.c:4248
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1338 [inline]
free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
free_unref_page_prepare mm/page_alloc.c:3309 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3388
slab_destroy mm/slab.c:1627 [inline]
slabs_destroy+0x89/0xc0 mm/slab.c:1647
cache_flusharray mm/slab.c:3418 [inline]
___cache_free+0x4cc/0x610 mm/slab.c:3480
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:259 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc mm/slab.c:3323 [inline]
kmem_cache_alloc+0x1bc/0x560 mm/slab.c:3507
sock_alloc_inode+0x18/0x1c0 net/socket.c:303
alloc_inode+0x61/0x230 fs/inode.c:235
new_inode_pseudo+0x14/0xe0 fs/inode.c:944
sock_alloc+0x3c/0x260 net/socket.c:626
__sock_create+0xb9/0x790 net/socket.c:1428
sock_create net/socket.c:1515 [inline]
__sys_socket+0xef/0x200 net/socket.c:1557
__do_sys_socket net/socket.c:1566 [inline]
__se_sys_socket net/socket.c:1564 [inline]
__x64_sys_socket+0x6f/0xb0 net/socket.c:1564
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

Memory state around the buggy address:
ffff888023e06780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888023e06800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888023e06880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888023e06900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888023e06980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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