linux-kernel - BUG: unable to handle kernel paging request in const_folio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <45a4da17.13ec7.197f8ec50fb.Coremail.baishuoran@hrbeu.edu.cn>
Date: Fri, 11 Jul 2025 17:58:46 +0800 (GMT+08:00)
From: 白烁冉 <baishuoran@...eu.edu.cn>
To: "Andrew Morton" <akpm@...ux-foundation.org>
Cc: "Kun Hu" <huk23@...udan.edu.cn>, "Jiaji Qin" <jjtan24@...udan.edu.cn>,
	syzkaller@...glegroups.com, linux-kernel@...r.kernel.org
Subject: BUG: unable to handle kernel paging request in const_folio_flags

Dear Maintainers,


When using our customized Syzkaller to fuzz the latest Linux kernel, the following crash (121th)was triggered.




HEAD commit: 6537cfb395f352782918d8ee7b7f10ba2cc3cbf2
git tree: upstream
Output: https://github.com/pghk13/Kernel-Bug/blob/main/0702_6.14/BUG%3A%20unable%20to%20handle%20kernel%20paging%20request%20in%20const_folio_flags/121report.txt
Kernel config:https://github.com/pghk13/Kernel-Bug/blob/main/0702_6.14/config.txt
C reproducer:https://github.com/pghk13/Kernel-Bug/blob/main/0702_6.14/BUG%3A%20unable%20to%20handle%20kernel%20paging%20request%20in%20const_folio_flags/121repro.c
Syzlang reproducer:https://github.com/pghk13/Kernel-Bug/blob/main/0702_6.14/BUG%3A%20unable%20to%20handle%20kernel%20paging%20request%20in%20const_folio_flags/121repro.txt

Our reproducer uses mounts a constructed filesystem image.
 
 This may be an error code mistakenly used as a pointer bug, occurring around line 308 of the code: 1. OCFS2 error handling issue: ocfs2_write_begin_nolock returns -ENOMEM (-12) when it encounters a memory allocation failure. 2. Incorrect error handling: In the error handling path, a certain function (most likely ocfs2_unlock_and_free_folios) incorrectly passed the error code -12 as a valid folio pointer to folio_unlock.

We have reproduced this issue several times on 6.14 again.






If you fix this issue, please add the following tag to the commit:
Reported-by: Kun Hu <huk23@...udan.edu.cn>, Jiaji Qin <jjtan24@...udan.edu.cn>, Shuoran Bai <baishuoran@...eu.edu.cn>

(syz.5.1560,31124,2):ocfs2_write_begin_nolock:1798 ERROR: status = -12
BUG: unable to handle page fault for address: fffffffffffffffc
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD df84067 P4D df84067 PUD df86067 
PMD 0 
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 31124 Comm: syz.5.1560 Not tainted 6.14.0 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:const_folio_flags.constprop.0+0x27/0x70
Code: 90 90 90 41 54 49 89 fc 53 e8 65 c3 ca ff 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 3e <49> 8b 5c 24 08 31 ff 83 e3 01 48 89 de e8 77 c5 ca ff 48 85 db 75
RSP: 0018:ffffc90011eef678 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff888079f54030 RCX: ffffffff839c06f7
RDX: 1fffffffffffffff RSI: ffff888059b2a480 RDI: fffffffffffffffc
RBP: fffffffffffffff4 R08: 0000000000000000 R09: fffffbfff20c2fa3
R10: fffffbfff20c2fa2 R11: ffffffff90617d17 R12: fffffffffffffff4
R13: 000000000000000e R14: dffffc0000000000 R15: 0000000000000001
FS:  00007f2d805f6700(0000) GS:ffff88802b900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffc CR3: 000000004039e000 CR4: 0000000000750ef0
PKRU: 80000000
Call Trace:
 <TASK>
 folio_unlock+0x16/0xd0
 ocfs2_unlock_and_free_folios+0x8c/0x1b0
 ocfs2_write_begin_nolock+0x115d/0x4f60
 ocfs2_write_begin+0x1d9/0x350
 generic_perform_write+0x3e0/0x8c0
 __generic_file_write_iter+0x1f6/0x240
 ocfs2_file_write_iter+0xc44/0x2380
 vfs_write+0xba2/0x1100
 ksys_write+0x122/0x240
 do_syscall_64+0xcf/0x250
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d827acadd
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2d805f5ba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2d829a5fa0 RCX: 00007f2d827acadd
RDX: 000000000000045c RSI: 0000000020000400 RDI: 0000000000000005
RBP: 00007f2d805f5c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f2d829a5fac R14: 00007f2d829a6038 R15: 00007f2d805f5d40
 </TASK>
Modules linked in:
CR2: fffffffffffffffc
---[ end trace 0000000000000000 ]---
RIP: 0010:const_folio_flags.constprop.0+0x27/0x70
Code: 90 90 90 41 54 49 89 fc 53 e8 65 c3 ca ff 49 8d 7c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 3e <49> 8b 5c 24 08 31 ff 83 e3 01 48 89 de e8 77 c5 ca ff 48 85 db 75
RSP: 0018:ffffc90011eef678 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff888079f54030 RCX: ffffffff839c06f7
RDX: 1fffffffffffffff RSI: ffff888059b2a480 RDI: fffffffffffffffc
RBP: fffffffffffffff4 R08: 0000000000000000 R09: fffffbfff20c2fa3
R10: fffffbfff20c2fa2 R11: ffffffff90617d17 R12: fffffffffffffff4
R13: 000000000000000e R14: dffffc0000000000 R15: 0000000000000001
FS:  00007f2d805f6700(0000) GS:ffff88802b900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffc CR3: 000000004039e000 CR4: 0000000000750ef0
PKRU: 80000000
----------------
Code disassembly (best guess):
   0: 90                    nop
   1: 90                    nop
   2: 90                    nop
   3: 41 54                push   %r12
   5: 49 89 fc              mov    %rdi,%r12
   8: 53                    push   %rbx
   9: e8 65 c3 ca ff        callq  0xffcac373
   e: 49 8d 7c 24 08        lea    0x8(%r12),%rdi
  13: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
  1a: fc ff df
  1d: 48 89 fa              mov    %rdi,%rdx
  20: 48 c1 ea 03          shr    $0x3,%rdx
  24: 80 3c 02 00          cmpb   $0x0,(%rdx,%rax,1)
  28: 75 3e                jne    0x68
* 2a: 49 8b 5c 24 08        mov    0x8(%r12),%rbx <-- trapping instruction
  2f: 31 ff                xor    %edi,%edi
  31: 83 e3 01              and    $0x1,%ebx
  34: 48 89 de              mov    %rbx,%rsi
  37: e8 77 c5 ca ff        callq  0xffcac5b3
  3c: 48 85 db              test   %rbx,%rbx
  3f: 75                    .byte 0x75



thanks,
Kun Hu