general protection fault in put_page

[Wei Chen]

Dear Linux Developer,

Recently when using our tool to fuzz kernel, the following crash was triggered:

HEAD commit: 31f4f5b495a6 Linux 5.4-rc7
git tree: upstream
compiler: clang 12.0.0
console output:
https://drive.google.com/file/d/1rjxlk2_QNsl6CcOwElvUSq5Yhcafb6Il/view?usp=sharing
Syzlang reproducer:
https://drive.google.com/file/d/1MFN7c56voPBkd7LzgO0mGZ_oOQNHyK-w/view?usp=sharing
kernel config: https://drive.google.com/file/d/1sFjtE830MyLBJYZzwZ9sJRsKdf5EzUTV/view?usp=sharing

However, we tried to use syz-prog2c to convert the Syzlang reproducer
to C format. But the crash wasn't reproduced by the C program. Please
use syz-execprog to execute the Syzlang reproducer directly on kernel
to reproduce the bug.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: Wei Chen <harperchen1110@xxxxxxxxx>

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: 16421 Comm: syz-executor Not tainted 5.4.0-rc7+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:put_page+0x25/0x1e0
Code: 00 00 00 00 00 55 41 57 41 56 41 54 53 49 89 fe 49 bc 00 00 00
00 00 fc ff df e8 96 b0 18 fd 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 80
3c 20 00 74 05 e8 3f 9a 53 fd 49 8b 6e 08 89 eb 83 e3 01 31
RSP: 0018:ffff888090927b60 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 1ffff1100bfc9c58 RCX: 0000000000040000
RDX: ffffc90001b01000 RSI: 0000000000005d4e RDI: 0000000000000008
RBP: 00000000fffffff2 R08: ffffffff84567149 R09: ffffed1014392357
R10: ffffed1014392357 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88805fe4ea00 R14: 0000000000000000 R15: ffff88805fe4e2c0
FS:  00007f3188c14700(0000) GS:ffff888064000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f318b71c930 CR3: 000000010b399000 CR4: 0000000000742ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 qp_host_get_user_memory+0x29f/0x540
 qp_broker_alloc+0x13aa/0x2850
 vmci_qp_broker_alloc+0x46/0x60
 vmci_host_unlocked_ioctl+0x1460/0x3080
 do_vfs_ioctl+0x7d2/0x18a0
 __x64_sys_ioctl+0xd9/0x120
 do_syscall_64+0xda/0x200
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f318b6aba3d
Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f3188c13c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f318b7d20a0 RCX: 00007f318b6aba3d
RDX: 0000000020000100 RSI: 00000000000007a8 RDI: 0000000000000003
RBP: 00007f318b724d80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f318b7d20a0
R13: 00007ffd7552eb3f R14: 00007ffd7552ece0 R15: 00007f3188c13dc0
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace bb9c6e0f73b79e40 ]---
RIP: 0010:put_page+0x25/0x1e0
Code: 00 00 00 00 00 55 41 57 41 56 41 54 53 49 89 fe 49 bc 00 00 00
00 00 fc ff df e8 96 b0 18 fd 49 8d 7e 08 48 89 f8 48 c1 e8 03 <42> 80
3c 20 00 74 05 e8 3f 9a 53 fd 49 8b 6e 08 89 eb 83 e3 01 31
RSP: 0018:ffff888090927b60 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 1ffff1100bfc9c58 RCX: 0000000000040000
RDX: ffffc90001b01000 RSI: 0000000000005d4e RDI: 0000000000000008
RBP: 00000000fffffff2 R08: ffffffff84567149 R09: ffffed1014392357
R10: ffffed1014392357 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88805fe4ea00 R14: 0000000000000000 R15: ffff88805fe4e2c0
FS:  00007f3188c14700(0000) GS:ffff888064000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f434ae59000 CR3: 000000010b399000 CR4: 0000000000742ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
----------------
Code disassembly (best guess):
   0: 00 00                add    %al,(%rax)
   2: 00 00                add    %al,(%rax)
   4: 00 55 41              add    %dl,0x41(%rbp)
   7: 57                    push   %rdi
   8: 41 56                push   %r14
   a: 41 54                push   %r12
   c: 53                    push   %rbx
   d: 49 89 fe              mov    %rdi,%r14
  10: 49 bc 00 00 00 00 00 movabs $0xdffffc0000000000,%r12
  17: fc ff df
  1a: e8 96 b0 18 fd        callq  0xfd18b0b5
  1f: 49 8d 7e 08          lea    0x8(%r14),%rdi
  23: 48 89 f8              mov    %rdi,%rax
  26: 48 c1 e8 03          shr    $0x3,%rax
* 2a: 42 80 3c 20 00        cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f: 74 05                je     0x36
  31: e8 3f 9a 53 fd        callq  0xfd539a75
  36: 49 8b 6e 08          mov    0x8(%r14),%rbp
  3a: 89 eb                mov    %ebp,%ebx
  3c: 83 e3 01              and    $0x1,%ebx
  3f: 31                    .byte 0x31

Best,
Wei