------------[ cut here ]------------
WARNING: CPU: 0 PID: 20418 at mm/mmap.c:965 vma_merge+0x170/0x818 mm/mmap.c:965
Modules linked in:
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 0 PID: 20418 Comm: syz-executor.1 Not tainted 6.4.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
Backtrace: 
[<817d9798>] (dump_backtrace) from [<817d988c>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:256)
 r7:00000000 r6:826229c4 r5:60000093 r4:81f9d60c
[<817d9874>] (show_stack) from [<817f6360>] (__dump_stack lib/dump_stack.c:88 [inline])
[<817d9874>] (show_stack) from [<817f6360>] (dump_stack_lvl+0x48/0x54 lib/dump_stack.c:106)
[<817f6318>] (dump_stack_lvl) from [<817f6384>] (dump_stack+0x18/0x1c lib/dump_stack.c:113)
 r5:00000000 r4:82850d14
[<817f636c>] (dump_stack) from [<817da384>] (panic+0x120/0x370 kernel/panic.c:340)
[<817da264>] (panic) from [<80241fe8>] (print_tainted+0x0/0xa0 kernel/panic.c:236)
 r3:8260c488 r2:00000001 r1:81f86700 r0:81f8e110
 r7:80465898
[<80241f64>] (check_panic_on_warn) from [<802421dc>] (__warn+0x7c/0x180 kernel/panic.c:673)
[<80242160>] (__warn) from [<802423b8>] (warn_slowpath_fmt+0xd8/0x1d8 kernel/panic.c:697)
 r8:00000009 r7:000003c5 r6:81fb248c r5:8260c964 r4:824adf7c
[<802422e4>] (warn_slowpath_fmt) from [<80465898>] (vma_merge+0x170/0x818 mm/mmap.c:965)
 r10:00000000 r9:00000000 r8:83300280 r7:20400000 r6:84c75478 r5:84c752c0
 r4:84c750b0
[<80465728>] (vma_merge) from [<80531d68>] (userfaultfd_register fs/userfaultfd.c:1485 [inline])
[<80465728>] (vma_merge) from [<80531d68>] (userfaultfd_ioctl+0x1268/0x1534 fs/userfaultfd.c:2050)
 r10:21000000 r9:84c75478 r8:20400000 r7:84c750b0 r6:00100277 r5:8606a000
 r4:ed039eb8
[<80530b00>] (userfaultfd_ioctl) from [<804e564c>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<80530b00>] (userfaultfd_ioctl) from [<804e564c>] (do_vfs_ioctl fs/ioctl.c:830 [inline])
[<80530b00>] (userfaultfd_ioctl) from [<804e564c>] (__do_sys_ioctl fs/ioctl.c:868 [inline])
[<80530b00>] (userfaultfd_ioctl) from [<804e564c>] (sys_ioctl+0x110/0xa74 fs/ioctl.c:856)
 r10:8516ef30 r9:00000003 r8:8404f6c0 r7:20000040 r6:8404f6c1 r5:00000000
 r4:c020aa00
[<804e553c>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:66)
Exception stack(0xed039fa8 to 0xed039ff0)
9fa0:                   00000000 00000000 00000003 c020aa00 20000040 00000000
9fc0: 00000000 00000000 0014c2b8 00000036 7ea9c3c2 76b526d0 7ea9c534 76b5220c
9fe0: 76b52020 76b52010 00017004 0004dfb0
 r10:00000036 r9:835e69c0 r8:80200288 r7:00000036 r6:0014c2b8 r5:00000000
 r4:00000000
Rebooting in 86400 seconds..