syzbot


KASAN: stack-out-of-bounds Read in finish_writeback_work

Status: auto-closed as invalid on 2020/02/17 22:28
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+357de617b97752833bd5@syzkaller.appspotmail.com
First crash: 1666d, last: 1641d
Discussions (1)
Title Replies (including bot) Last reply
KASAN: stack-out-of-bounds Read in finish_writeback_work 0 (1) 2019/10/25 08:38

Sample crash report:
==================================================================
BUG: KASAN: stack-out-of-bounds in finish_writeback_work.isra.0+0x11b/0x120 fs/fs-writeback.c:168
Read of size 8 at addr ffff88806f04f9c8 by task kworker/u4:2/33

CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 5.4.0-rc1+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 finish_writeback_work.isra.0+0x11b/0x120 fs/fs-writeback.c:168
 wb_do_writeback fs/fs-writeback.c:2030 [inline]
 wb_workfn+0x34f/0x1220 fs/fs-writeback.c:2070
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the page:
page:ffffea0001bc13c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffffff01bc0101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88806f04f880: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1
 ffff88806f04f900: f1 00 00 f3 f3 00 00 00 00 00 00 00 00 00 00 00
>ffff88806f04f980: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3
                                              ^
 ffff88806f04fa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
 ffff88806f04fa80: f1 f1 f1 00 f2 f2 f2 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/20 22:27 bpf 05679ca6feeb 8c88c9c1 .config console log report ci-upstream-bpf-kasan-gce
2019/10/14 17:42 net-old 33902b4a4227 05ad7292 .config console log report ci-upstream-net-this-kasan-gce
2019/10/08 22:20 net-old 503c9addef61 b1ebbfef .config console log report ci-upstream-net-this-kasan-gce
2019/09/27 17:10 bpf 768fb61fcc13 d8074e0b .config console log report ci-upstream-bpf-kasan-gce
2019/09/26 15:09 net-old 99dcb8432af0 24d405a3 .config console log report ci-upstream-net-this-kasan-gce
2019/10/06 09:57 bpf-next a53ba15d8199 f3f7d9c8 .config console log report ci-upstream-bpf-next-kasan-gce
2019/09/28 16:26 net-next-old b41dae061bbd eb6b9855 .config console log report ci-upstream-net-kasan-gce
2019/09/28 13:43 bpf-next b41dae061bbd eb6b9855 .config console log report ci-upstream-bpf-next-kasan-gce
2019/09/27 11:39 net-next-old b41dae061bbd 2f1548bc .config console log report ci-upstream-net-kasan-gce
2019/09/26 17:51 net-next-old b41dae061bbd 24d405a3 .config console log report ci-upstream-net-kasan-gce
2019/09/26 14:22 bpf-next b41dae061bbd 24d405a3 .config console log report ci-upstream-bpf-next-kasan-gce
2019/09/25 18:40 net-next-old b41dae061bbd a3355dba .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.