syzbot


WARNING in wp_page_copy

Status: fixed on 2020/11/16 12:12
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+9301f2f33873407d5b33@syzkaller.appspotmail.com
Fix commit: c3e5ea6ee574 mm: avoid data corruption on CoW fault into PFN-mapped VMA
First crash: 1639d, last: 1558d
Cause bisection: introduced by (bisect log) :
commit 83d116c53058d505ddef051e90ab27f57015b025
Author: Jia He <justin.he@arm.com>
Date: Fri Oct 11 14:09:39 2019 +0000

  mm: fix double page fault on arm64 if PTE_AF is cleared

Crash: WARNING in wp_page_copy (log)
Repro: syz .config
  
Fix bisection: fixed by (bisect log) :
commit c3e5ea6ee574ae5e845a40ac8198de1fb63bb3ab
Author: Kirill A. Shutemov <kirill@shutemov.name>
Date: Fri Mar 6 06:28:32 2020 +0000

  mm: avoid data corruption on CoW fault into PFN-mapped VMA

  
Discussions (1)
Title Replies (including bot) Last reply
WARNING in wp_page_copy 9 (13) 2020/11/11 13:34
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2020/03/23 23:14 3h31m bisect fix upstream job log (1)
2020/02/17 12:35 21m bisect fix upstream job log (0) log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9882 at mm/memory.c:2229 cow_user_page mm/memory.c:2229 [inline]
WARNING: CPU: 1 PID: 9882 at mm/memory.c:2229 wp_page_copy+0x10b7/0x1560 mm/memory.c:2414
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9882 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:cow_user_page mm/memory.c:2229 [inline]
RIP: 0010:wp_page_copy+0x10b7/0x1560 mm/memory.c:2414
Code: 4c 89 f7 ba 00 10 00 00 48 81 e6 00 f0 ff ff e8 3f f2 22 06 31 ff 41 89 c7 89 c6 e8 23 03 d3 ff 45 85 ff 74 0f e8 99 01 d3 ff <0f> 0b 4c 89 f7 e8 6f e4 22 06 e8 8a 01 d3 ff 65 4c 8b 34 25 c0 1e
RSP: 0000:ffffc90002017ab8 EFLAGS: 00010293
RAX: ffff888091f60600 RBX: ffffc90002017d68 RCX: ffffffff81a229ed
RDX: 0000000000000000 RSI: ffffffff81a229f7 RDI: 0000000000000005
RBP: ffffc90002017bf8 R08: ffff888091f60600 R09: 0000000000000000
R10: ffffed100fb44fff R11: ffff88807da27fff R12: ffff88809591c840
R13: ffffea0001f689c0 R14: ffff88807da27000 R15: 0000000000001000
 do_wp_page+0x543/0x1540 mm/memory.c:2724
 handle_pte_fault mm/memory.c:3961 [inline]
 __handle_mm_fault+0x327b/0x3da0 mm/memory.c:4075
 handle_mm_fault+0x3b2/0xa50 mm/memory.c:4112
 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline]
 __do_page_fault+0x536/0xd80 arch/x86/mm/fault.c:1506
 do_page_fault+0x38/0x590 arch/x86/mm/fault.c:1530
 page_fault+0x39/0x40 arch/x86/entry/entry_64.S:1203
RIP: 0033:0x4006c4
Code: 01 e9 c9 00 00 00 48 8b 44 24 10 48 0b 44 24 28 be 08 00 00 00 48 8b 14 24 75 17 48 8b 7c 24 20 e8 91 54 00 00 48 8b 4c 24 08 <48> 89 01 e9 9d 00 00 00 48 8b 44 24 08 48 8b 38 e8 77 54 00 00 8a
RSP: 002b:00007ffcb8657510 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000200016c0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: 0000000000761160 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffcb8657610 R11: 0000000000000246 R12: 000000000075bf20
R13: 0000000000000005 R14: 0000000000761168 R15: 000000000075bf2c
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/14 22:17 upstream e31736d9fae8 eef6e580 .config console log report syz ci-upstream-kasan-gce-selinux-root
2019/12/14 21:58 net-old 5c9934b6767b eef6e580 .config console log report syz ci-upstream-net-this-kasan-gce
2019/12/14 16:19 net-next-old 1d1997db870f eef6e580 .config console log report syz ci-upstream-net-kasan-gce
2019/12/18 01:20 upstream 9065e0636036 a6bc9c88 .config console log report ci-upstream-kasan-gce
2020/01/18 12:35 net-old 5a9ef19454cd 3de7aabb .config console log report ci-upstream-net-this-kasan-gce
2019/11/28 15:35 net-old a6ed68d6468b 46869e3e .config console log report ci-upstream-net-this-kasan-gce
2019/12/14 15:17 net-next-old 1d1997db870f eef6e580 .config console log report ci-upstream-net-kasan-gce
2019/12/03 07:04 net-next-old 596cf45cbf6e ab342da3 .config console log report ci-upstream-net-kasan-gce
2019/11/30 15:52 net-next-old 81b6b96475ac 3a75be00 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.