Re: invalid opcode in map_vdso
From: Borislav Petkov
Date: Wed Sep 23 2020 - 06:30:19 EST
On Wed, Sep 23, 2020 at 11:19:40AM +0200, Dmitry Vyukov wrote:
> +clang-built-linux
> Looks like another one with kernel code overwrite in clang build.
Uuh, that's a nice and refreshing one - the pattern is not zeroes this
time
Code: 16 48 89 ef 48 8b 34 24 31 c9 e8 88 7c a7 00 eb 7a 4c 8b 74 24 28 43 80 3c 3e 00 48 8b 5c 24 08 74 08 4c 89 ef e8 4d 77 70 70 <07> 20 05 00 00 49 03 6d 00 48 89 e8 48 c1 e8 03 42 80 3c 38 00 74
All code
========
0: 16 (bad)
1: 48 89 ef mov %rbp,%rdi
4: 48 8b 34 24 mov (%rsp),%rsi
8: 31 c9 xor %ecx,%ecx
a: e8 88 7c a7 00 callq 0xa77c97
f: eb 7a jmp 0x8b
11: 4c 8b 74 24 28 mov 0x28(%rsp),%r14
16: 43 80 3c 3e 00 cmpb $0x0,(%r14,%r15,1)
1b: 48 8b 5c 24 08 mov 0x8(%rsp),%rbx
20: 74 08 je 0x2a
22: 4c 89 ef mov %r13,%rdi
25: e8 4d 77 70 70 callq 0x70707777
2a:* 07 (bad) <-- trapping instruction
2b: 20 05 00 00 49 03 and %al,0x3490000(%rip) # 0x3490031
31: 6d insl (%dx),%es:(%rdi)
32: 00 48 89 add %cl,-0x77(%rax)
35: e8 48 c1 e8 03 callq 0x3e8c182
3a: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
3f: 74 .byte 0x74
Code starting with the faulting instruction
===========================================
0: 07 (bad)
1: 20 05 00 00 49 03 and %al,0x3490000(%rip) # 0x3490007
7: 6d insl (%dx),%es:(%rdi)
8: 00 48 89 add %cl,-0x77(%rax)
b: e8 48 c1 e8 03 callq 0x3e8c158
10: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
15: 74 .byte 0x74
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette