syzbot

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 76f5c067 P4D 76f5c067 PUD 8a46f067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 13287 Comm: syz-executor.4 Not tainted 6.4.0-rc4-syzkaller-00031-g8b817fded42d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003e2efd8 EFLAGS: 00010246
RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffffffff8b25a7e0
RDX: ffffc90003e2f340 RSI: ffffc90003e2f320 RDI: ffff888029d2c000
RBP: ffffc90003e2f510 R08: ffffffff834f660b R09: ffffed100426760d
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920007c5e6c
R13: dffffc0000000000 R14: ffffc90003e2f301 R15: 0000000000000001
FS:  00007f05c8b89700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000095b8a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 nilfs_segctor_assign fs/nilfs2/segment.c:1651 [inline]
 nilfs_segctor_do_construct+0x39f1/0x6d30 fs/nilfs2/segment.c:2081
 nilfs_construct_dsync_segment+0x5c4/0x6c0 fs/nilfs2/segment.c:2335
 nilfs_sync_file+0xbc/0x260 fs/nilfs2/file.c:32
 generic_write_sync include/linux/fs.h:2469 [inline]
 generic_file_write_iter+0x2a1/0x310 mm/filemap.c:4087
 do_iter_write+0x7b1/0xcb0 fs/read_write.c:860
 iter_file_splice_write+0x843/0xfe0 fs/splice.c:795
 do_splice_from fs/splice.c:873 [inline]
 direct_splice_actor+0xe7/0x1c0 fs/splice.c:1039
 splice_direct_to_actor+0x4c4/0xbd0 fs/splice.c:994
 do_splice_direct+0x283/0x3d0 fs/splice.c:1082
 do_sendfile+0x620/0xff0 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f05c7e8c169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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:00007f05c8b89168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f05c7fabf80 RCX: 00007f05c7e8c169
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 00007f05c7ee7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffd9c19f0f R14: 00007f05c8b89300 R15: 0000000000022000
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc90003e2efd8 EFLAGS: 00010246
RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffffffff8b25a7e0
RDX: ffffc90003e2f340 RSI: ffffc90003e2f320 RDI: ffff888029d2c000
RBP: ffffc90003e2f510 R08: ffffffff834f660b R09: ffffed100426760d
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920007c5e6c
R13: dffffc0000000000 R14: ffffc90003e2f301 R15: 0000000000000001
FS:  00007f05c8b89700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000095b8a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400