ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
------------[ cut here ]------------
kernel BUG at mm/filemap.c:868!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 21109 Comm: syz.2.4350 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__filemap_add_folio+0x11ad/0x12f0 mm/filemap.c:867
Code: 50 c9 ff 4c 89 e7 48 c7 c6 a0 3d b4 8b e8 bb 4a 31 ff 90 0f 0b e8 13 50 c9 ff 4c 89 e7 48 c7 c6 80 34 b4 8b e8 a4 4a 31 ff 90 <0f> 0b e8 fc 4f c9 ff 4c 89 e7 48 c7 c6 a0 3d b4 8b e8 8d 4a 31 ff
RSP: 0018:ffffc9000400f2a0 EFLAGS: 00010246
RAX: 782380b0ae7c8c00 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000007 RSI: ffffffff8dc91f97 RDI: 00000000ffffffff
RBP: ffffc9000400f410 R08: ffffffff8fe4c437 R09: 1ffffffff1fc9886
R10: dffffc0000000000 R11: fffffbfff1fc9887 R12: ffffea00017a3d00
R13: dffffc0000000000 R14: ffffea00017a3d08 R15: 0000000000000003
FS:  00007fd2f34356c0(0000) GS:ffff8881257db000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6646972020 CR3: 000000003c280000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 filemap_add_folio+0xd5/0x270 mm/filemap.c:969
 ra_alloc_folio mm/readahead.c:448 [inline]
 page_cache_ra_order+0x643/0xd40 mm/readahead.c:506
 do_sync_mmap_readahead+0x25e/0x7a0 mm/filemap.c:-1
 filemap_fault+0x62c/0x1200 mm/filemap.c:3446
 __do_fault+0x138/0x390 mm/memory.c:5152
 do_cow_fault mm/memory.c:5603 [inline]
 do_fault mm/memory.c:5709 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault+0x1719/0x5440 mm/memory.c:6195
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364
 faultin_page mm/gup.c:1144 [inline]
 __get_user_pages+0x1699/0x2ce0 mm/gup.c:1446
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880
 __mm_populate+0x24c/0x380 mm/gup.c:1983
 mm_populate include/linux/mm.h:3374 [inline]
 vm_mmap_pgoff+0x387/0x4d0 mm/util.c:585
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604
 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: 0033:0x7fd2f258ebe9
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:00007fd2f3435038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fd2f27b6090 RCX: 00007fd2f258ebe9
RDX: 0000000000000002 RSI: 0000000000004000 RDI: 0000200000945000
RBP: 00007fd2f2611e19 R08: 0000000000000003 R09: 00000000202a0000
R10: 0000000000026052 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd2f27b6128 R14: 00007fd2f27b6090 R15: 00007ffdbad4cb28
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__filemap_add_folio+0x11ad/0x12f0 mm/filemap.c:867
Code: 50 c9 ff 4c 89 e7 48 c7 c6 a0 3d b4 8b e8 bb 4a 31 ff 90 0f 0b e8 13 50 c9 ff 4c 89 e7 48 c7 c6 80 34 b4 8b e8 a4 4a 31 ff 90 <0f> 0b e8 fc 4f c9 ff 4c 89 e7 48 c7 c6 a0 3d b4 8b e8 8d 4a 31 ff
RSP: 0018:ffffc9000400f2a0 EFLAGS: 00010246
RAX: 782380b0ae7c8c00 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000007 RSI: ffffffff8dc91f97 RDI: 00000000ffffffff
RBP: ffffc9000400f410 R08: ffffffff8fe4c437 R09: 1ffffffff1fc9886
R10: dffffc0000000000 R11: fffffbfff1fc9887 R12: ffffea00017a3d00
R13: dffffc0000000000 R14: ffffea00017a3d08 R15: 0000000000000003
FS:  00007fd2f34356c0(0000) GS:ffff8881258db000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3056f17286 CR3: 000000003c280000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000006800 DR2: 0000000000009951
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400