On Sat, Dec 19, 2020 at 12:46:37PM +0100, John Wood wrote: > Hi, > > I'm working in a new LSM to detect and mitigate any fork brute force > attack against vulnerable userspace processes. I'm testing the detection > method but I have found some problems that I think are related to locking > since the kernel gets stuck but not crashes. This work is a WIP to obtain > the v3 version. The mitigation, documentation and fine tunning detection > are under construction. > > My problem is that I don't be able to find the cause of this behaviour and > any help would be greatly appreciated. I think that I have found the cause of the problem. I acquired the brute_stats_ptr_lock in the task_fatal_signal hook without disable interrupts. Then, the task_free hook was call from an IRQ context and tried to acquire the same lock in a write state. This cause a deadlock. Thanks anyway, John Wood _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
