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

syzbot
2021-11-03T23:16:44Z

Hello,

syzbot found the following issue on:

HEAD commit: cc0356d6a02e Merge tag 'x86_core_for_v5.16_rc1' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14058b96b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a5d447cdc3ae81d9
dashboard link: https://syzkaller.appspot.com/bug?extid=3587cbbc6e1868796292
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+3587cbbc6e1868796292@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:167 [inline]
BUG: KASAN: use-after-free in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: use-after-free in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: use-after-free in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: use-after-free in iocb_put fs/aio.c:1161 [inline]
BUG: KASAN: use-after-free in io_submit_one+0x6fb/0x1b80 fs/aio.c:1882
Write of size 4 at addr ffff88803d5bf5c8 by task syz-executor.1/25125

CPU: 0 PID: 25125 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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+0x6c/0x309 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:167 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
iocb_put fs/aio.c:1161 [inline]
io_submit_one+0x6fb/0x1b80 fs/aio.c:1882
__do_sys_io_submit fs/aio.c:1938 [inline]
__se_sys_io_submit fs/aio.c:1908 [inline]
__x64_sys_io_submit+0x18c/0x330 fs/aio.c:1908
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
RIP: 0033:0x7f881ae57ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f88183cd188 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f881af6af60 RCX: 00007f881ae57ae9
RDX: 00000000200000c0 RSI: 0000000000000001 RDI: 00007f881af4e000
RBP: 00007f881aeb1f25 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc3b5fd44f R14: 00007f88183cd300 R15: 0000000000022000
</TASK>

Allocated by task 25125:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x83/0xb0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:259 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3213 [inline]
slab_alloc mm/slub.c:3221 [inline]
kmem_cache_alloc+0x209/0x390 mm/slub.c:3226
aio_get_req fs/aio.c:1028 [inline]
io_submit_one+0xfd/0x1b80 fs/aio.c:1875
__do_sys_io_submit fs/aio.c:1938 [inline]
__se_sys_io_submit fs/aio.c:1908 [inline]
__x64_sys_io_submit+0x18c/0x330 fs/aio.c:1908
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 25125:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1700 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1726
slab_free mm/slub.c:3492 [inline]
kmem_cache_free+0x95/0x5d0 mm/slub.c:3508
iocb_destroy fs/aio.c:1080 [inline]
iocb_put fs/aio.c:1163 [inline]
iocb_put fs/aio.c:1159 [inline]
aio_complete_rw+0x474/0x8c0 fs/aio.c:1440
aio_rw_done fs/aio.c:1510 [inline]
aio_read+0x30d/0x460 fs/aio.c:1537
__io_submit_one fs/aio.c:1830 [inline]
io_submit_one+0xe2b/0x1b80 fs/aio.c:1879
__do_sys_io_submit fs/aio.c:1938 [inline]
__se_sys_io_submit fs/aio.c:1908 [inline]
__x64_sys_io_submit+0x18c/0x330 fs/aio.c:1908
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

The buggy address belongs to the object at ffff88803d5bf500
which belongs to the cache aio_kiocb of size 216
The buggy address is located 200 bytes inside of
216-byte region [ffff88803d5bf500, ffff88803d5bf5d8)
The buggy address belongs to the page:
page:ffffea0000f56fc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d5bf
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea000211f880 0000000200000002 ffff888145dae280
raw: 0000000000000000 00000000800c000c 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 22913, ts 1044095753625, free_ts 1044067792778
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4155
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5381
alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
alloc_slab_page mm/slub.c:1770 [inline]
allocate_slab mm/slub.c:1907 [inline]
new_slab+0x319/0x490 mm/slub.c:1970
___slab_alloc+0x921/0xfe0 mm/slub.c:3001
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3088
slab_alloc_node mm/slub.c:3179 [inline]
slab_alloc mm/slub.c:3221 [inline]
kmem_cache_alloc+0x363/0x390 mm/slub.c:3226
aio_get_req fs/aio.c:1028 [inline]
io_submit_one+0xfd/0x1b80 fs/aio.c:1875
__do_sys_io_submit fs/aio.c:1938 [inline]
__se_sys_io_submit fs/aio.c:1908 [inline]
__x64_sys_io_submit+0x18c/0x330 fs/aio.c:1908
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
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare+0x326/0x810 mm/page_alloc.c:1391
free_unref_page_prepare mm/page_alloc.c:3317 [inline]
free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3433
release_pages+0x3f4/0x1480 mm/swap.c:970
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
tlb_flush_mmu mm/mmu_gather.c:249 [inline]
tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340
exit_mmap+0x1ea/0x630 mm/mmap.c:3173
__mmput+0x122/0x4b0 kernel/fork.c:1114
mmput+0x56/0x60 kernel/fork.c:1135
exit_mm kernel/exit.c:502 [inline]
do_exit+0xab8/0x2a20 kernel/exit.c:813
do_group_exit+0x125/0x310 kernel/exit.c:923
get_signal+0x47d/0x21d0 kernel/signal.c:2855
arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
handle_signal_work kernel/entry/common.c:148 [inline]
exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
exit_to_user_mode_prepare+0x17d/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

Memory state around the buggy address:
ffff88803d5bf480: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88803d5bf500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803d5bf580: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
^
ffff88803d5bf600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff88803d5bf680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

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