Re: futex local DoS on most architectures

From: Riku Voipio
Date: Tue Feb 12 2008 - 07:53:18 EST


Thomas Gleixner wrote:
We have to disable the complete PI/robust functionality for those
archs, which do not implement futex_atomic_cmpxchg_inatomic(). The
code in question relies on a valid implementation and does not expect
-ENOSYS, which is returned by the stub implementation in
asm-generic/futex.h

Pointed out by: Mikael Pettersson, Riku Voipio and Adrian Bunk
Original credits for finding this issue belong to Lennert Buytenhek.
This patch is intended for easy backporting and needs to be cleaned up
further for current mainline.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Looks good for me and kernel no longer deadlocks with this patch!
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