Thank you for providing the code and identifying the potential vulnerability. The vulnerability you've mentioned (CWE-476: NULL Pointer Dereference) doesn't seem to be directly applicable to the line you've highlighted (line 13). However, I'll provide five possible patches that could improve the robustness of the code around that line, assuming there might be some underlying issues we're not seeing in the provided snippet.

Patch 1:
```c
if (ticks_from_now < 0) {
    return;
}
abs_time = ble_npl_time_get() + ticks_from_now;
```

Patch 2:
```c
ble_npl_time_t current_time = ble_npl_time_get();
if (current_time == (ble_npl_time_t)-1) {
    // Handle error condition
    return;
}
abs_time = current_time + ticks_from_now;
```

Patch 3:
```c
#define MAX_TICKS_FROM_NOW 0x7FFFFFFF
if (ticks_from_now > MAX_TICKS_FROM_NOW) {
    ticks_from_now = MAX_TICKS_FROM_NOW;
}
abs_time = ble_npl_time_get() + ticks_from_now;
```

Patch 4:
```c
ble_npl_time_t current_time = ble_npl_time_get();
if (__builtin_add_overflow(current_time, ticks_from_now, &abs_time)) {
    // Handle overflow condition
    return;
}
```

Patch 5:
```c
ble_npl_time_t current_time = ble_npl_time_get();
abs_time = (ticks_from_now > 0) ? current_time + ticks_from_now : current_time;
```

These patches aim to address potential issues such as negative input, overflow, and error conditions from the time-getting function. However, without more context about the specific vulnerability or the behavior of the `ble_npl_time_get()` function, it's challenging to provide more targeted fixes. Always ensure to test thoroughly after applying any patches.