general protection fault in free_verifier_state (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    6dd42aa1 Merge branch 'runqslower'
git tree:       bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14e61349e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a736c99e9fe5a676
dashboard link: https://syzkaller.appspot.com/bug?extid=b296579ba5015704d9fa
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b296579ba5015704d9fa@xxxxxxxxxxxxxxxxxxxxxxxxx

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3213 Comm: syz-executor.2 Not tainted 5.5.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:free_verifier_state+0x49/0x1d0 kernel/bpf/verifier.c:744
Code: db 48 83 ec 20 48 89 45 b8 48 c1 e8 03 4c 01 f8 89 75 c4 48 89 45 c8  
e8 65 ae f2 ff 4c 63 f3 4f 8d 2c f4 4c 89 e8 48 c1 e8 03 <42> 80 3c 38 00  
0f 85 2b 01 00 00 4f 8d 34 f4 49 8b 3e 48 85 ff 48
RSP: 0018:ffffc900017c7688 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000d65b000
RDX: 0000000000040000 RSI: ffffffff818251eb RDI: 0000000000000000
RBP: ffffc900017c76d0 R08: ffff88806f496640 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fdb4648e700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000010f6e80 CR3: 00000000690e9000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 do_check_common+0x2ec7/0x9650 kernel/bpf/verifier.c:9597
 do_check_main kernel/bpf/verifier.c:9654 [inline]
 bpf_check+0x84ed/0xbb07 kernel/bpf/verifier.c:10009
 bpf_prog_load+0xeab/0x17f0 kernel/bpf/syscall.c:1859
 __do_sys_bpf+0x1269/0x37a0 kernel/bpf/syscall.c:3096
 __se_sys_bpf kernel/bpf/syscall.c:3055 [inline]
 __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:3055
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdb4648dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000000000024 RSI: 0000000020000200 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdb4648e6d4
R13: 00000000004c1697 R14: 00000000004d66a0 R15: 00000000ffffffff
Modules linked in:
---[ end trace d725571ef2f4cce3 ]---
RIP: 0010:free_verifier_state+0x49/0x1d0 kernel/bpf/verifier.c:744
Code: db 48 83 ec 20 48 89 45 b8 48 c1 e8 03 4c 01 f8 89 75 c4 48 89 45 c8  
e8 65 ae f2 ff 4c 63 f3 4f 8d 2c f4 4c 89 e8 48 c1 e8 03 <42> 80 3c 38 00  
0f 85 2b 01 00 00 4f 8d 34 f4 49 8b 3e 48 85 ff 48
RSP: 0018:ffffc900017c7688 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc9000d65b000
RDX: 0000000000040000 RSI: ffffffff818251eb RDI: 0000000000000000
RBP: ffffc900017c76d0 R08: ffff88806f496640 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fdb4648e700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000075c000 CR3: 00000000690e9000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.