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BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map

Status: upstream: reported C repro on 2026/03/19 02:00
Reported-by: syzbot+54013d63871351b9f5de@syzkaller.appspotmail.com
First crash: 49d, last: 4d13h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2026/04/22 upstream (ToT) 6596a02b2078 C Failed due to an error; will retry later
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 general protection fault in nilfs_mdt_save_to_shadow_map origin:upstream 2 C 19 7d02h 33d 0/3 upstream: reported C repro on 2026/04/03 15:20
upstream general protection fault in nilfs_mdt_save_to_shadow_map nilfs 2 C error 87 23d 51d 28/29 upstream: reported C repro on 2026/03/17 03:14
linux-6.6 general protection fault in nilfs_mdt_save_to_shadow_map origin:lts-only 2 C error 12 17d 21d 0/2 upstream: reported C repro on 2026/04/16 08:31

Sample crash report:
NILFS (loop0): invalid segment: Checksum error in segment payload
NILFS (loop0): trying rollback from an earlier position
NILFS (loop0): recovery complete
Unable to handle kernel paging request at virtual address dfff800000000006
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006
  CM = 0, WnR = 0
[dfff800000000006] address between user and kernel address ranges
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4473 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : nilfs_mdt_save_to_shadow_map+0x134/0x1b4 fs/nilfs2/mdt.c:549
lr : nilfs_mdt_save_to_shadow_map+0xcc/0x1b4 fs/nilfs2/mdt.c:545
sp : ffff800020e576c0
x29: ffff800020e576c0 x28: ffff7000041caef0 x27: dfff800000000000
x26: ffff0000d1e26678 x25: ffff800020e57a40 x24: ffff0000ea2d07c0
x23: dfff800000000000 x22: 0000000000000030 x21: ffff0000ea2d1050
x20: ffff0000d7a5ad40 x19: ffff0000ea2d0158 x18: 0000000000000000
x17: ffff800018349000 x16: ffff8000082d7ca0 x15: 0000000000000000
x14: 0000000000000406 x13: 0000000000ff0100 x12: 0000000000ff0100
x11: ff00800009c4f514 x10: 0000000000000000 x9 : ffff0000c2ca1bc0
x8 : 0000000000000006 x7 : ffff8000086f165c x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 nilfs_mdt_save_to_shadow_map+0x134/0x1b4 fs/nilfs2/mdt.c:549
 nilfs_clean_segments+0x124/0x870 fs/nilfs2/segment.c:2512
 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline]
 nilfs_ioctl+0x22c0/0x2660 fs/nilfs2/ioctl.c:1304
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: 97b258b5 f94002c8 9100c116 d343fec8 (38776908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	97b258b5 	bl	0xfffffffffec962d4
   4:	f94002c8 	ldr	x8, [x22]
   8:	9100c116 	add	x22, x8, #0x30
   c:	d343fec8 	lsr	x8, x22, #3
* 10:	38776908 	ldrb	w8, [x8, x23] <-- trapping instruction

Crashes (28):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/19 02:53 linux-6.1.y f2ddafa93a25 0199f9a1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/03/19 02:28 linux-6.1.y f2ddafa93a25 0199f9a1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/05/02 20:35 linux-6.1.y 4931e0e1673d a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/20 01:29 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/20 01:29 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/20 01:04 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/20 01:00 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/20 00:59 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/19 11:15 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/16 04:59 linux-6.1.y 8e8fc038cad5 df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/10 13:36 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/09 12:06 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/06 22:58 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/03/27 04:40 linux-6.1.y 1989cd3d56e2 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/03/22 09:54 linux-6.1.y f2ddafa93a25 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/03/22 01:45 linux-6.1.y f2ddafa93a25 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/03/19 02:00 linux-6.1.y f2ddafa93a25 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: unable to handle kernel paging request in nilfs_mdt_save_to_shadow_map
2026/04/24 21:33 linux-6.1.y 7c87defbd336 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/24 21:33 linux-6.1.y 7c87defbd336 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/20 01:46 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/20 01:46 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/20 01:27 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/20 01:21 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/20 01:19 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/19 11:36 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/19 11:36 linux-6.1.y 7c87defbd336 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/16 08:10 linux-6.1.y 8e8fc038cad5 df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
2026/04/16 08:09 linux-6.1.y 8e8fc038cad5 df15c5f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan general protection fault in nilfs_mdt_save_to_shadow_map
* Struck through repros no longer work on HEAD.