------------[ cut here ]------------
pgoff != vma->vm_start >> 12
WARNING: mm/vma.h:277 at assert_sane_pgoff mm/vma.h:277 [inline], CPU#0: syz.0.17/5928
WARNING: mm/vma.h:277 at vma_set_pgoff mm/vma.h:283 [inline], CPU#0: syz.0.17/5928
WARNING: mm/vma.h:277 at vma_add_pgoff mm/vma.h:314 [inline], CPU#0: syz.0.17/5928
WARNING: mm/vma.h:277 at __split_vma+0x162b/0x1de0 mm/vma.c:607, CPU#0: syz.0.17/5928
Modules linked in:
CPU: 0 UID: 0 PID: 5928 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:assert_sane_pgoff mm/vma.h:277 [inline]
RIP: 0010:vma_set_pgoff mm/vma.h:283 [inline]
RIP: 0010:vma_add_pgoff mm/vma.h:314 [inline]
RIP: 0010:__split_vma+0x162b/0x1de0 mm/vma.c:607
Code: 3c 02 00 0f 85 b1 07 00 00 4d 8b 27 48 89 ef 49 c1 ec 0c 4c 89 e6 e8 e4 1c 9e ff 4c 39 e5 0f 84 63 fc ff ff e8 f6 22 9e ff 90 <0f> 0b 90 e9 55 fc ff ff e8 e8 22 9e ff 48 8b 54 24 30 48 b8 00 00
RSP: 0018:ffffc90006147860 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888034873d10 RCX: 0000000000000000
RDX: ffff88802c0fa580 RSI: ffffffff826dcd1a RDI: ffff88802c0fa580
RBP: 0000000200000a98 R08: 0000000000000006 R09: 0000000200000a98
R10: 0000000200000002 R11: 0000000000000000 R12: 0000000200000002
R13: ffff888034873d40 R14: ffffc90006147e20 R15: ffff888034873cc0
FS:  000055556505a500(0000) GS:ffff8880d5b61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcf25070050 CR3: 000000003d074000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 vms_gather_munmap_vmas+0x1d2/0x1720 mm/vma.c:1507
 do_vmi_align_munmap+0x287/0x5f0 mm/vma.c:1675
 do_vmi_munmap+0x1f8/0x3e0 mm/vma.c:1732
 __vm_munmap+0x196/0x390 mm/vma.c:3390
 __do_sys_munmap mm/mmap.c:1094 [inline]
 __se_sys_munmap mm/mmap.c:1091 [inline]
 __x64_sys_munmap+0x59/0x80 mm/mmap.c:1091
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf2519e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc13ebea08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 00007fcf25425fa0 RCX: 00007fcf2519e159
RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000200000002000
RBP: 00007fcf25235024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcf25425fac R14: 00007fcf25425fa0 R15: 00007fcf25425fa0
 </TASK>