------------[ cut here ]------------
pgoff != vma->vm_start >> 12
WARNING: mm/vma.h:276 at assert_sane_pgoff mm/vma.h:276 [inline], CPU#2: syz.0.17/5920
WARNING: mm/vma.h:276 at vma_set_pgoff mm/vma.h:282 [inline], CPU#2: syz.0.17/5920
WARNING: mm/vma.h:276 at vma_add_pgoff mm/vma.h:289 [inline], CPU#2: syz.0.17/5920
WARNING: mm/vma.h:276 at __split_vma+0x1228/0x1800 mm/vma.c:578, CPU#2: syz.0.17/5920
Modules linked in:
CPU: 2 UID: 0 PID: 5920 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:276 [inline]
RIP: 0010:vma_set_pgoff mm/vma.h:282 [inline]
RIP: 0010:vma_add_pgoff mm/vma.h:289 [inline]
RIP: 0010:__split_vma+0x1228/0x1800 mm/vma.c:578
Code: 3c 02 00 0f 85 d3 05 00 00 4c 8b 2b 48 89 ef 49 c1 ed 0c 4c 89 ee e8 a7 3d 9e ff 4c 39 ed 0f 84 bf fd ff ff e8 b9 43 9e ff 90 <0f> 0b 90 e9 b1 fd ff ff e8 ab 43 9e ff 48 8b 54 24 38 48 b8 00 00
RSP: 0018:ffffc9000344f228 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88803e4b23c0 RCX: 0000000000000000
RDX: ffff888030d0a580 RSI: ffffffff826cbe17 RDI: ffff888030d0a580
RBP: 0000000200000003 R08: 0000000000000006 R09: 0000000200000003
R10: 0000000200000ffd R11: 0000000000000000 R12: ffff88803e4b2410
R13: 0000000200000ffd R14: ffffc9000344f5c8 R15: 0000000000000000
FS:  000055555d60b500(0000) GS:ffff8880d5da2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff66f270000 CR3: 000000001345e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 vms_gather_munmap_vmas+0x1d2/0x1720 mm/vma.c:1472
 __mmap_setup mm/vma.c:2496 [inline]
 __mmap_region+0x4a7/0x30b0 mm/vma.c:2818
 mmap_region+0x5a8/0x6d0 mm/vma.c:2921
 do_mmap+0x12c7/0x1c30 mm/mmap.c:573
 vm_mmap_pgoff+0x28d/0x470 mm/util.c:581
 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:619
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 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: 0033:0x7ff66f39e0d9
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:00007ffec1164ee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff66f625fa0 RCX: 00007ff66f39e0d9
RDX: 0000000000000001 RSI: 0000000000003000 RDI: 0000200000ffd000
RBP: 00007ff66f435024 R08: 0000000000000004 R09: 0000010000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff66f625fac R14: 00007ff66f625fa0 R15: 00007ff66f625fa0
 </TASK>