syzbot


WARNING in pagemap_scan_pmd_entry (2)

Status: upstream: reported C repro on 2024/02/09 18:51
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+0748a3a1931714d970d0@syzkaller.appspotmail.com
First crash: 65d, last: 2d04h
Cause bisection: introduced by (bisect log) :
commit 12f6b01a0bcbeeab8cc9305673314adb3adf80f7
Author: Muhammad Usama Anjum <usama.anjum@collabora.com>
Date: Mon Aug 21 14:15:15 2023 +0000

  fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag

Crash: WARNING in pagemap_scan_pmd_entry (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fs?] WARNING in pagemap_scan_pmd_entry (2) 0 (1) 2024/02/09 18:51
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in pagemap_scan_pmd_entry fs C inconclusive 48 128d 150d 25/26 fixed on 2024/01/20 21:18
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/03/02 22:00 19m retest repro upstream report log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5069 at arch/x86/include/asm/pgtable.h:404 pte_uffd_wp arch/x86/include/asm/pgtable.h:404 [inline]
WARNING: CPU: 1 PID: 5069 at arch/x86/include/asm/pgtable.h:404 pagemap_scan_pmd_entry+0xa15/0x2e10 fs/proc/task_mmu.c:2195
Modules linked in:
CPU: 1 PID: 5069 Comm: syz-executor103 Not tainted 6.8.0-rc3-syzkaller-00041-g547ab8fc4cb0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:pte_uffd_wp arch/x86/include/asm/pgtable.h:404 [inline]
RIP: 0010:pagemap_scan_pmd_entry+0xa15/0x2e10 fs/proc/task_mmu.c:2195
Code: 2d 67 ff 83 e3 42 bf 40 00 00 00 48 89 de e8 b2 32 67 ff 48 83 fb 40 0f 85 6d fe ff ff e8 c3 2d 67 ff eb 05 e8 bc 2d 67 ff 90 <0f> 0b 90 e9 5d fe ff ff e8 ae 2d 67 ff 31 c0 48 89 44 24 20 4d 89
RSP: 0018:ffffc9000395f5c0 EFLAGS: 00010293
RAX: ffffffff822c3974 RBX: 07ffffffffff040a RCX: ffff888023abbb80
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffffc9000395f830 R08: ffffffff822c393b R09: fffff5200072be88
R10: dffffc0000000000 R11: fffff5200072be88 R12: dffffc0000000000
R13: 000000002007d000 R14: ffffc9000395f740 R15: ffff888023eef3e0
FS:  000055555572c380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200007c8 CR3: 0000000075868000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 walk_pmd_range mm/pagewalk.c:143 [inline]
 walk_pud_range mm/pagewalk.c:221 [inline]
 walk_p4d_range mm/pagewalk.c:256 [inline]
 walk_pgd_range+0xba1/0x17e0 mm/pagewalk.c:293
 __walk_page_range+0x132/0x720 mm/pagewalk.c:395
 walk_page_range+0x4c8/0x6c0 mm/pagewalk.c:521
 do_pagemap_scan fs/proc/task_mmu.c:2471 [inline]
 do_pagemap_cmd+0xb11/0x1340 fs/proc/task_mmu.c:2513
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:857
 do_syscall_64+0xf9/0x240
 entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7f948bf61b69
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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:00007ffffdc7d4d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffffdc7d510 RCX: 00007f948bf61b69
RDX: 00000000200007c0 RSI: 00000000c0606610 RDI: 0000000000000004
RBP: 00007ffffdc7d510 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffffdc7d4f0 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/08 04:46 upstream 547ab8fc4cb0 6404acf9 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in pagemap_scan_pmd_entry
2024/04/11 22:58 upstream 480e035fc4c7 478efa7f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in pagemap_scan_pmd_entry
2024/04/04 11:37 upstream 480e035fc4c7 51c4dcff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in pagemap_scan_pmd_entry
2024/02/17 18:31 upstream c1ca10ceffbb 578f7538 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in pagemap_scan_pmd_entry
2024/02/08 04:21 upstream 547ab8fc4cb0 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in pagemap_scan_pmd_entry
* Struck through repros no longer work on HEAD.