syzbot


KASAN: use-after-free Read in io_ring_ctx_wait_and_kill

Status: closed as dup on 2020/12/23 23:17
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+fef004c4db2d363bacd3@syzkaller.appspotmail.com
First crash: 1227d, last: 1219d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
WARNING in percpu_ref_kill_and_confirm (2) fs C done 71 1218d 1227d
Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in io_ring_ctx_wait_and_kill 1 (2) 2020/12/23 23:14

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:938 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x102f/0x1110 kernel/locking/mutex.c:1103
Read of size 8 at addr ffff88814a1be3e0 by task syz-executor.3/30767

CPU: 1 PID: 30767 Comm: syz-executor.3 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:396 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
 __mutex_lock_common kernel/locking/mutex.c:938 [inline]
 __mutex_lock+0x102f/0x1110 kernel/locking/mutex.c:1103
 io_ring_ctx_wait_and_kill+0x21/0x450 fs/io_uring.c:8648
 io_uring_release+0x3e/0x50 fs/io_uring.c:8687
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xb89/0x2a00 kernel/exit.c:823
 do_group_exit+0x125/0x310 kernel/exit.c:920
 get_signal+0x3e9/0x2160 kernel/signal.c:2770
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e149
Code: Unable to access opcode bytes at RIP 0x45e11f.
RSP: 002b:00007f10716b9be8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9
RAX: fffffffffffffff4 RBX: 0000000020000180 RCX: 000000000045e149
RDX: 00000000206d4000 RSI: 0000000020000180 RDI: 0000000000000087
RBP: 000000000119c080 R08: 0000000020000040 R09: 0000000020000040
R10: 0000000020000100 R11: 0000000000000206 R12: 00000000206d4000
R13: 0000000020ffd000 R14: 0000000020000040 R15: 0000000020000100

Allocated by task 30767:
 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:401 [inline]
 ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:682 [inline]
 io_ring_ctx_alloc fs/io_uring.c:1268 [inline]
 io_uring_create fs/io_uring.c:9480 [inline]
 io_uring_setup+0x1d5b/0x38b0 fs/io_uring.c:9613
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 25579:
 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:354
 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362
 kasan_slab_free include/linux/kasan.h:188 [inline]
 slab_free_hook mm/slub.c:1547 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1580
 slab_free mm/slub.c:3143 [inline]
 kfree+0xdb/0x3c0 mm/slub.c:4125
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:342
 insert_work+0x48/0x370 kernel/workqueue.c:1331
 __queue_work+0x5c1/0xfb0 kernel/workqueue.c:1497
 queue_work_on+0xc7/0xd0 kernel/workqueue.c:1524
 io_uring_create fs/io_uring.c:9586 [inline]
 io_uring_setup+0x1358/0x38b0 fs/io_uring.c:9613
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Second to last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:342
 __call_rcu kernel/rcu/tree.c:2965 [inline]
 call_rcu+0xbb/0x710 kernel/rcu/tree.c:3038
 put_event kernel/events/core.c:4935 [inline]
 perf_event_release_kernel+0xa5e/0xe40 kernel/events/core.c:5050
 perf_release+0x33/0x40 kernel/events/core.c:5060
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88814a1be000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 992 bytes inside of
 2048-byte region [ffff88814a1be000, ffff88814a1be800)
The buggy address belongs to the page:
page:00000000e5c1a3cf refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14a1b8
head:00000000e5c1a3cf order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head)
raw: 057ff00000010200 dead000000000100 dead000000000122 ffff888010842000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88814a1be280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88814a1be300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88814a1be380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88814a1be400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88814a1be480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/24 09:15 upstream 58cf05f597b0 c2c1d1dd .config console log report info ci-upstream-kasan-gce
2020/12/23 13:36 upstream 614cb5894306 c2c1d1dd .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/22 04:37 upstream 8653b778e454 04201c06 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/21 18:04 upstream e37b12e4bb21 04201c06 .config console log report info ci-upstream-kasan-gce
2020/12/21 16:09 upstream e37b12e4bb21 04201c06 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/20 23:10 upstream 6a447b0e3151 04201c06 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/20 14:21 upstream 467f8165a2b0 04201c06 .config console log report info ci-upstream-kasan-gce
2020/12/20 05:15 upstream 467f8165a2b0 04201c06 .config console log report info ci-upstream-kasan-gce
2020/12/19 06:49 upstream a409ed156a90 04201c06 .config console log report info ci-upstream-kasan-gce
2020/12/18 21:26 upstream a409ed156a90 04201c06 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/22 00:31 upstream e37b12e4bb21 04201c06 .config console log report info ci-upstream-kasan-gce-386
2020/12/19 09:45 upstream 3644e2d2dda7 04201c06 .config console log report info ci-upstream-kasan-gce-386
2020/12/22 11:33 linux-next 6c3eb1b174c0 04201c06 .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/21 07:42 linux-next 4c6ed015c2a5 04201c06 .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/21 01:32 linux-next 0d52778b8710 04201c06 .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/19 20:18 linux-next 0d52778b8710 04201c06 .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/18 09:25 linux-next 0d52778b8710 04201c06 .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/16 07:23 linux-next 9317f948b0b1 f213e07e .config console log report info ci-upstream-linux-next-kasan-gce-root
2020/12/16 01:18 linux-next 9317f948b0b1 97183ed7 .config console log report info ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.