kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6920 Comm: syz-executor.4 Not tainted 4.19.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unlink_anon_vmas+0x63/0x840 mm/rmap.c:385
Code: 3c 02 00 0f 85 77 07 00 00 48 8b 44 24 10 48 8b 58 78 48 b8 00 00 00 00 00 fc ff df 48 8d 6b f0 48 89 da 49 89 df 48 c1 ea 03 <80> 3c 02 00 0f 85 3f 07 00 00 48 8b 03 48 39 5c 24 08 4c 8d 68 f0
RSP: 0018:ffff888228f478d0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff818b264c
RDX: 0000000000000000 RSI: ffffffff818ff7bb RDI: ffff888000103630
RBP: fffffffffffffff0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000000
R13: 0000001b30920000 R14: 0000001b2f920000 R15: 0000000000000000
FS:  00007f6627e88700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564f9ad3a628 CR3: 0000000082b40000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 free_pgtables+0x1ab/0x2f0 mm/memory.c:652
 exit_mmap+0x2c8/0x530 mm/mmap.c:3094
 __mmput kernel/fork.c:1015 [inline]
 mmput+0x14e/0x4a0 kernel/fork.c:1036
 exit_mm kernel/exit.c:549 [inline]
 do_exit+0xaec/0x2be0 kernel/exit.c:857
 do_group_exit+0x125/0x310 kernel/exit.c:967
 get_signal+0x3f2/0x1f70 kernel/signal.c:2589
 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466459
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6627e88218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056bf68 RCX: 0000000000466459
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68
RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c
R13: 00007ffecb409ecf R14: 00007f6627e88300 R15: 0000000000022000
Modules linked in:
---[ end trace 5b0c531aa011cad2 ]---
RIP: 0010:unlink_anon_vmas+0x63/0x840 mm/rmap.c:385
Code: 3c 02 00 0f 85 77 07 00 00 48 8b 44 24 10 48 8b 58 78 48 b8 00 00 00 00 00 fc ff df 48 8d 6b f0 48 89 da 49 89 df 48 c1 ea 03 <80> 3c 02 00 0f 85 3f 07 00 00 48 8b 03 48 39 5c 24 08 4c 8d 68 f0
RSP: 0018:ffff888228f478d0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff818b264c
RDX: 0000000000000000 RSI: ffffffff818ff7bb RDI: ffff888000103630
RBP: fffffffffffffff0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000000 R12: 0000000000000000
R13: 0000001b30920000 R14: 0000001b2f920000 R15: 0000000000000000
FS:  00007f6627e88700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000540198 CR3: 0000000082b40000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400