BUG: unable to handle page fault for address: fffffffffffffc98 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD df3d067 P4D df3d067 PUD df3f067 PMD 0 Oops: Oops: 0002 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 7881 Comm: syz.3.257 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:bch2_writepage_io_alloc fs/bcachefs/fs-io-buffered.c:516 [inline] RIP: 0010:__bch2_writepage+0x15b7/0x2790 fs/bcachefs/fs-io-buffered.c:644 Code: ff e8 3d 24 e9 fd 49 81 c6 98 fc ff ff 4d 89 37 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 1e 24 e9 fd 48 8b 44 24 68 <49> 89 06 4d 8b 37 48 8b 94 24 a0 00 00 00 48 89 d0 48 c1 e8 03 0f RSP: 0018:ffffc900053e7168 EFLAGS: 00010246 RAX: ffff88804ee00798 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc9000d1eb000 RSI: 00000000000015e7 RDI: 00000000000015e8 RBP: 0000000000000008 R08: ffff888051548908 R09: 1ffffd40002a6ac8 R10: dffffc0000000000 R11: fffff940002a6ac9 R12: 1ffff92000a7ce7c R13: 0000000000000008 R14: fffffffffffffc98 R15: ffffc900053e73e0 FS: 00007f90ca3666c0(0000) GS:ffff888125d93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffc98 CR3: 000000002937c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: write_cache_pages+0x64/0x100 mm/page-writeback.c:2614 bch2_writepages+0x154/0x360 fs/bcachefs/fs-io-buffered.c:675 do_writepages+0x32b/0x550 mm/page-writeback.c:2636 filemap_fdatawrite_wbc mm/filemap.c:386 [inline] __filemap_fdatawrite_range mm/filemap.c:419 [inline] file_write_and_wait_range+0x22c/0x330 mm/filemap.c:794 bch2_fsync+0x127/0x330 fs/bcachefs/fs-io.c:245 generic_write_sync include/linux/fs.h:3027 [inline] bch2_write_iter+0x2822/0x2b90 fs/bcachefs/fs-io-buffered.c:1097 do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f90c958e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f90ca366038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007f90c97b5fa0 RCX: 00007f90c958e969 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000008 RBP: 00007f90c9610ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000e7b R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f90c97b5fa0 R15: 00007fffc1948f58 Modules linked in: CR2: fffffffffffffc98 ---[ end trace 0000000000000000 ]--- RIP: 0010:bch2_writepage_io_alloc fs/bcachefs/fs-io-buffered.c:516 [inline] RIP: 0010:__bch2_writepage+0x15b7/0x2790 fs/bcachefs/fs-io-buffered.c:644 Code: ff e8 3d 24 e9 fd 49 81 c6 98 fc ff ff 4d 89 37 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 4c 89 f7 e8 1e 24 e9 fd 48 8b 44 24 68 <49> 89 06 4d 8b 37 48 8b 94 24 a0 00 00 00 48 89 d0 48 c1 e8 03 0f RSP: 0018:ffffc900053e7168 EFLAGS: 00010246 RAX: ffff88804ee00798 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc9000d1eb000 RSI: 00000000000015e7 RDI: 00000000000015e8 RBP: 0000000000000008 R08: ffff888051548908 R09: 1ffffd40002a6ac8 R10: dffffc0000000000 R11: fffff940002a6ac9 R12: 1ffff92000a7ce7c R13: 0000000000000008 R14: fffffffffffffc98 R15: ffffc900053e73e0 FS: 00007f90ca3666c0(0000) GS:ffff888125d93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffc98 CR3: 000000002937c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 3d 24 e9 fd call 0xfde92442 5: 49 81 c6 98 fc ff ff add $0xfffffffffffffc98,%r14 c: 4d 89 37 mov %r14,(%r15) f: 4c 89 f0 mov %r14,%rax 12: 48 c1 e8 03 shr $0x3,%rax 16: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 1a: 74 08 je 0x24 1c: 4c 89 f7 mov %r14,%rdi 1f: e8 1e 24 e9 fd call 0xfde92442 24: 48 8b 44 24 68 mov 0x68(%rsp),%rax * 29: 49 89 06 mov %rax,(%r14) <-- trapping instruction 2c: 4d 8b 37 mov (%r15),%r14 2f: 48 8b 94 24 a0 00 00 mov 0xa0(%rsp),%rdx 36: 00 37: 48 89 d0 mov %rdx,%rax 3a: 48 c1 e8 03 shr $0x3,%rax 3e: 0f .byte 0xf