syzbot


KASAN: use-after-free Read in io_sq_wq_submit_work

Status: upstream: reported C repro on 2020/08/31 03:21
Reported-by: syzbot+e0edd00a47204c0ba7eb@syzkaller.appspotmail.com
First crash: 828d, last: 796d

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x98/0x100 lib/list_debug.c:54
Read of size 8 at addr ffff8881ce189780 by task kworker/u4:2/158

CPU: 1 PID: 158 Comm: kworker/u4:2 Not tainted 5.4.61-syzkaller-00873-ge15cc541b749 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: io_ring-wq io_sq_wq_submit_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x14a/0x1ce lib/dump_stack.c:118
 print_address_description+0x93/0x620 mm/kasan/report.c:374
 __kasan_report+0x16d/0x1e0 mm/kasan/report.c:506
 kasan_report+0x36/0x60 mm/kasan/common.c:634
 __list_del_entry_valid+0x98/0x100 lib/list_debug.c:54
 __list_del_entry include/linux/list.h:131 [inline]
 list_del_init include/linux/list.h:190 [inline]
 io_sq_wq_submit_work+0x7f5/0x14a0 fs/io_uring.c:2272
 process_one_work+0x777/0xf90 kernel/workqueue.c:2274
 worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420
 kthread+0x317/0x340 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 329:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x12c/0x1c0 mm/kasan/common.c:510
 slab_post_alloc_hook mm/slab.h:584 [inline]
 kmem_cache_alloc_bulk+0x1cf/0x250 mm/slub.c:3233
 io_get_req+0x27f/0x850 fs/io_uring.c:650
 io_submit_sqe+0x83/0xe90 fs/io_uring.c:2560
 io_ring_submit fs/io_uring.c:2948 [inline]
 __do_sys_io_uring_enter fs/io_uring.c:3825 [inline]
 __se_sys_io_uring_enter+0x922/0x1ff0 fs/io_uring.c:3786
 do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 158:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x181/0x230 mm/kasan/common.c:471
 slab_free_hook mm/slub.c:1443 [inline]
 slab_free_freelist_hook+0xd0/0x150 mm/slub.c:1476
 slab_free mm/slub.c:3041 [inline]
 kmem_cache_free+0xac/0x600 mm/slub.c:3057
 io_put_req fs/io_uring.c:762 [inline]
 io_poll_complete_work+0x737/0x940 fs/io_uring.c:1835
 process_one_work+0x777/0xf90 kernel/workqueue.c:2274
 worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420
 kthread+0x317/0x340 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881ce189680
 which belongs to the cache io_kiocb of size 264
The buggy address is located 256 bytes inside of
 264-byte region [ffff8881ce189680, ffff8881ce189788)
The buggy address belongs to the page:
page:ffffea0007386200 refcount:1 mapcount:0 mapping:ffff8881d99ba500 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881d99ba500
raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881ce189680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881ce189700: fb fb f

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-4-kasan 2020/08/31 03:38 https://android.googlesource.com/kernel/common android-5.4 e15cc541b749 d5a3ae1f .config log report syz C
ci2-android-5-4-kasan 2020/10/02 03:46 android12-5.4 2a7d52383a14 9602ddf4 .config log report info
ci2-android-5-4-kasan 2020/08/31 03:20 https://android.googlesource.com/kernel/common android-5.4 e15cc541b749 d5a3ae1f .config log report
* Struck through repros no longer work on HEAD.