BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 92ed5067 P4D 92ed5067 PUD 90360067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13725 Comm: syz-executor.2 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:ffffc9000345ec98 EFLAGS: 00010246 RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffffffff8b25a7e0 RDX: ffffc9000345f000 RSI: ffffc9000345efe0 RDI: ffff88806ed8b000 RBP: ffffc9000345f1d0 R08: ffffffff834f660b R09: ffffed100f378681 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200068be04 R13: dffffc0000000000 R14: ffffc9000345f001 R15: 0000000000000001 FS: 00007f716bfe9700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000778ca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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 do_writepages+0x3a6/0x670 mm/page-writeback.c:2551 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] filemap_write_and_wait_range+0x1d4/0x2c0 mm/filemap.c:678 __generic_file_write_iter+0x2c8/0x400 mm/filemap.c:4037 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4083 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: 0033:0x7f716b28c169 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:00007f716bfe9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f716b3abf80 RCX: 00007f716b28c169 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005 RBP: 00007f716b2e7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0001000000201005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe4dfed0af R14: 00007f716bfe9300 R15: 0000000000022000 Modules linked in: CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffffc9000345ec98 EFLAGS: 00010246 RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffffffff8b25a7e0 RDX: ffffc9000345f000 RSI: ffffc9000345efe0 RDI: ffff88806ed8b000 RBP: ffffc9000345f1d0 R08: ffffffff834f660b R09: ffffed100f378681 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200068be04 R13: dffffc0000000000 R14: ffffc9000345f001 R15: 0000000000000001 FS: 00007f716bfe9700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000000778ca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400