syzbot


WARNING in untrack_pfn

Status: upstream: reported C repro on 2023/07/19 07:05
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+e68f8778d06d8e37ebbb@syzkaller.appspotmail.com
First crash: 670d, last: 8d04h
Fix commit to backport (bisect log) :
tree: upstream
commit d155df53f31068c3340733d586eb9b3ddfd70fc5
Author: Ma Wupeng <mawupeng1@huawei.com>
Date: Fri Feb 17 02:56:15 2023 +0000

  x86/mm/pat: clear VM_PAT if copy_p4d_range failed

  
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: WARNING in untrack_pfn (log)
Repro: C syz .config
  
Bug presence (2)
Date Name Commit Repro Result
2024/10/31 linux-5.15.y (ToT) 74cdd62cb470 C [report] WARNING in untrack_pfn
2024/10/31 upstream (ToT) 0fc810ae3ae1 C Didn't crash
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in untrack_pfn kernel C done error 128 419d 2491d 0/28 auto-obsoleted due to no activity on 2024/07/03 15:42
android-49 WARNING in untrack_pfn syz 35 1993d 2227d 0/3 public: reported syz repro on 2019/04/14 09:28
linux-4.19 WARNING in untrack_pfn C error 24 852d 2113d 0/1 upstream: reported C repro on 2019/08/05 09:38
linux-4.14 WARNING in untrack_pfn C inconclusive 27 845d 2106d 0/1 upstream: reported C repro on 2019/08/13 08:40
android-44 WARNING in untrack_pfn C 211 2259d 2632d 0/2 closed as invalid on 2019/03/16 01:21
android-414 WARNING in untrack_pfn syz 1 2339d 2228d 0/1 public: reported syz repro on 2019/04/13 00:01
linux-6.1 WARNING in untrack_pfn (2) origin:lts-only C done 4 499d 623d 0/3 upstream: reported C repro on 2023/09/04 06:46
linux-6.1 WARNING in untrack_pfn 2 757d 765d 0/3 auto-obsoleted due to no activity on 2023/08/21 02:48
android-44 WARNING in untrack_pfn (2) C 71 1993d 2230d 0/2 public: reported C repro on 2019/04/11 08:44
Last patch testing requests (7)
Created Duration User Patch Repo Result
2025/05/11 11:36 12m kevinpaul468@gmail.com patch linux-5.15.y report log
2025/05/11 10:34 10m kevinpaul468@gmail.com patch linux-5.15.y report log
2025/05/11 04:56 10m retest repro linux-5.15.y report log
2025/03/22 16:10 9m retest repro linux-5.15.y report log
2025/01/09 20:12 11m retest repro linux-5.15.y report log
2024/10/12 14:46 8m retest repro linux-5.15.y report log
2024/10/12 14:46 18m retest repro linux-5.15.y OK log
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2023/11/22 14:51 5h34m fix candidate upstream OK (1) job log
2023/10/31 02:53 1h04m bisect fix linux-5.15.y OK (0) job log log
2023/09/27 03:00 52m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
R10: 0000000000000011 R11: 0000000000000246 R12: 00007f26c3761618
R13: 00007fff240e31b8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4160 at arch/x86/mm/pat/memtype.c:1020 get_pat_info arch/x86/mm/pat/memtype.c:1020 [inline]
WARNING: CPU: 1 PID: 4160 at arch/x86/mm/pat/memtype.c:1020 untrack_pfn+0x389/0x400 arch/x86/mm/pat/memtype.c:1122
Modules linked in:
CPU: 1 PID: 4160 Comm: syz-executor588 Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:get_pat_info arch/x86/mm/pat/memtype.c:1020 [inline]
RIP: 0010:untrack_pfn+0x389/0x400 arch/x86/mm/pat/memtype.c:1122
Code: 45 85 e4 49 bd 00 00 00 00 00 fc ff df 74 71 e8 5d 78 41 00 4c 8b 64 24 10 4d 85 e4 75 ac e8 4e 78 41 00 eb 11 e8 47 78 41 00 <0f> 0b 49 bd 00 00 00 00 00 fc ff df 48 c7 44 24 20 0e 36 e0 45 4a
RSP: 0018:ffffc90002fdf6c0 EFLAGS: 00010293
RAX: ffffffff81364529 RBX: 1ffff920005fbedc RCX: ffff8880225a1dc0
RDX: 0000000000000000 RSI: 0000000000000028 RDI: 0000000000000020
RBP: ffffc90002fdf7b8 R08: 0000000000000000 R09: ffffc90002fdf670
R10: fffffbfff1ad1706 R11: 1ffffffff1ad1705 R12: ffff88802a81b470
R13: ffff88802a81b420 R14: 0000000000000028 R15: 00000000ffffffea
FS:  000055556ec88380(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562e38d25000 CR3: 000000002a1e0000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unmap_single_vma+0x1c1/0x2b0 mm/memory.c:1600
 zap_page_range_single+0x292/0x380 mm/memory.c:1704
 remap_pfn_range_notrack+0x9a2/0xa00 mm/memory.c:2464
 remap_pfn_range+0xed/0x160 mm/memory.c:2489
 call_mmap include/linux/fs.h:2177 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1784 [inline]
 mmap_region+0xd0d/0x15e0 mm/mmap.c:2921
 do_mmap+0x77a/0xdf0 mm/mmap.c:1574
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:551
 ksys_mmap_pgoff+0x542/0x780 mm/mmap.c:1623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f26c36f6329
Code: 48 83 c4 28 c3 e8 17 1a 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff240e2fc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fff240e2fe0 RCX: 00007f26c36f6329
RDX: 000000000100000e RSI: 0000000000001000 RDI: 0000200000ffc000
RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000100000000
R10: 0000000000000011 R11: 0000000000000246 R12: 00007f26c3761618
R13: 00007fff240e31b8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/26 21:16 linux-5.15.y f7347f400572 c6b4fb39 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/11/18 22:07 linux-5.15.y 80529b4968a8 cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2025/04/26 20:56 linux-5.15.y f7347f400572 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/12/08 12:46 linux-5.15.y 8a1d809b0545 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/11/27 20:04 linux-5.15.y 2a910f4af54d 7ec6c044 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/11/18 19:12 linux-5.15.y 80529b4968a8 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/11/01 01:03 linux-5.15.y 12952a23a5da 58499c95 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/09/29 23:32 linux-5.15.y b911329317b4 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
2023/07/19 07:05 linux-5.15.y d54cfc420586 022df2bb .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in untrack_pfn
* Struck through repros no longer work on HEAD.