glGetFloatv causes stack smash

This causes a stack smash when compiled with GCC.

void MyOpenGLLineClass::set_width (float x)
{
    float max = 1;

    glGetFloatv (GL_ALIASED_LINE_WIDTH_RANGE, &max);

    if (false == (x > 0 && x <= max))
        throw std::invalid_argument (__PRETTY_FUNCTION__);

    m_width = x;
}

It happens in a program which otherwise behaves as expected. If I comment-out the glGetFloatv the stack smash goes away.

Here is the machine code:

   0x00005555556503be <+0>:     push   %rbp
   0x00005555556503bf <+1>:     mov    %rsp,%rbp
   0x00005555556503c2 <+4>:     push   %r12
   0x00005555556503c4 <+6>:     push   %rbx
   0x00005555556503c5 <+7>:     sub    $0x20,%rsp
   0x00005555556503c9 <+11>:    callq  *0x2e2bf9(%rip)        # 0x555555932fc8
   0x00005555556503cf <+17>:    mov    %rdi,-0x28(%rbp)
   0x00005555556503d3 <+21>:    movss  %xmm0,-0x2c(%rbp)
   0x00005555556503d8 <+26>:    mov    %fs:0x28,%rax
   0x00005555556503e1 <+35>:    mov    %rax,-0x18(%rbp)
   0x00005555556503e5 <+39>:    xor    %eax,%eax
   0x00005555556503e7 <+41>:    pxor   %xmm0,%xmm0
   0x00005555556503eb <+45>:    movss  %xmm0,-0x1c(%rbp)
   0x00005555556503f0 <+50>:    lea    -0x1c(%rbp),%rax
   0x00005555556503f4 <+54>:    mov    %rax,%rsi
   0x00005555556503f7 <+57>:    mov    $0x846e,%edi
   0x00005555556503fc <+62>:    callq  0x5555556262d0 <glGetFloatv@plt>
   0x0000555555650401 <+67>:    movss  -0x2c(%rbp),%xmm0
   0x0000555555650406 <+72>:    pxor   %xmm1,%xmm1
   0x000055555565040a <+76>:    comiss %xmm1,%xmm0
   0x000055555565040d <+79>:    seta   %al
   0x0000555555650410 <+82>:    xor    $0x1,%eax
   0x0000555555650413 <+85>:    test   %al,%al
   0x0000555555650415 <+87>:    jne    0x55555565042a <MyOpenGLLineClass::set_width(float)+108>
   0x0000555555650417 <+89>:    movss  -0x1c(%rbp),%xmm0
   0x000055555565041c <+94>:    comiss -0x2c(%rbp),%xmm0
   0x0000555555650420 <+98>:    setae  %al
   0x0000555555650423 <+101>:   xor    $0x1,%eax
   0x0000555555650426 <+104>:   test   %al,%al
   0x0000555555650428 <+106>:   je     0x55555565045f <MyOpenGLLineClass::set_width(float)+161>
   0x000055555565042a <+108>:   mov    $0x10,%edi
   0x000055555565042f <+113>:   callq  0x555555626130 <__cxa_allocate_exception@plt>
   0x0000555555650434 <+118>:   mov    %rax,%rbx
   0x0000555555650437 <+121>:   lea    0x8ee42(%rip),%rsi        # 0x5555556df280 <_ZZN3CMyOpenGLLineClass9set_widthEfE19__PRETTY_FUNCTION__>
   0x000055555565043e <+128>:   mov    %rbx,%rdi
   0x0000555555650441 <+131>:   callq  0x555555625f80 <_ZNSt16invalid_argumentC1EPKc@plt>
   0x0000555555650446 <+136>:   mov    0x2e2b5b(%rip),%rax        # 0x555555932fa8
   0x000055555565044d <+143>:   mov    %rax,%rdx
   0x0000555555650450 <+146>:   lea    0x2de9f1(%rip),%rsi        # 0x55555592ee48 <_ZTISt16invalid_argument@@GLIBCXX_3.4>
   0x0000555555650457 <+153>:   mov    %rbx,%rdi
   0x000055555565045a <+156>:   callq  0x555555625a80 <__cxa_throw@plt>
   0x000055555565045f <+161>:   mov    -0x28(%rbp),%rax
   0x0000555555650463 <+165>:   movss  -0x2c(%rbp),%xmm0
   0x0000555555650468 <+170>:   movss  %xmm0,0x58(%rax)
   0x000055555565046d <+175>:   nop
   0x000055555565046e <+176>:   mov    -0x18(%rbp),%rax
   0x0000555555650472 <+180>:   xor    %fs:0x28,%rax
   0x000055555565047b <+189>:   je     0x55555565049a <MyOpenGLLineClass::set_width(float)+220>
   0x000055555565047d <+191>:   jmp    0x555555650495 <MyOpenGLLineClass::set_width(float)+215>
   0x000055555565047f <+193>:   mov    %rax,%r12
   0x0000555555650482 <+196>:   mov    %rbx,%rdi
   0x0000555555650485 <+199>:   callq  0x5555556263c0 <__cxa_free_exception@plt>
   0x000055555565048a <+204>:   mov    %r12,%rax
   0x000055555565048d <+207>:   mov    %rax,%rdi
   0x0000555555650490 <+210>:   callq  0x555555625b00 <_Unwind_Resume@plt>
   0x0000555555650495 <+215>:   callq  0x5555556258a0 <__stack_chk_fail@plt>
=> 0x000055555565049a <+220>:   add    $0x20,%rsp
   0x000055555565049e <+224>:   pop    %rbx
   0x000055555565049f <+225>:   pop    %r12
   0x00005555556504a1 <+227>:   pop    %rbp
   0x00005555556504a2 <+228>:   retq

Why is this stack smash happening?

According to the Khronos reference, glGetFloatv with GL_ALIASED_LINE_WIDTH_RANGE returns two values:

GL_ALIASED_LINE_WIDTH_RANGE

params returns two values, the smallest and largest supported widths for aliased lines.

So the second value invokes UB and smashes your stack.

Fixed:

void MyOpenGLLineClass::set_width (float x)
{
    float range[] = {0,0};

    glGetFloatv (GL_ALIASED_LINE_WIDTH_RANGE, range);

    if (false == (x >= range[0] && x <= range[1]))
        throw std::invalid_argument (__PRETTY_FUNCTION__);

    m_width = x;
}