ladybird/Tests/Kernel/null-deref-crash-during-pthread_join.cpp
Andreas Kling 8c5cd97b45 Kernel: Fix kernel null deref on process crash during join_thread()
The join_thread() syscall is not supposed to be interruptible by
signals, but it was. And since the process death mechanism piggybacked
on signal interrupts, it was possible to interrupt a pthread_join() by
killing the process that was doing it, leading to confusing due to some
assumptions being made by Thread::finalize() for threads that have a
pending joiner.

This patch fixes the issue by making "interrupted by death" a distinct
block result separate from "interrupted by signal". Then we handle that
state in join_thread() and tidy things up so that thread finalization
doesn't get confused by the pending joiner being gone.

Test: Tests/Kernel/null-deref-crash-during-pthread_join.cpp
2020-01-10 19:23:45 +01:00

22 lines
374 B
C++

#include <pthread.h>
#include <stdio.h>
#include <sys/select.h>
#include <unistd.h>
int main(int, char**)
{
pthread_t tid;
pthread_create(
&tid, nullptr, [](void*) -> void* {
sleep(1);
asm volatile("ud2");
return nullptr;
},
nullptr);
pthread_join(tid, nullptr);
printf("ok\n");
return 0;
}