18 Nov
2021
18 Nov
'21
1:32 a.m.
On Wed, Nov 17, 2021 at 05:20:33PM -0800, Kyle Huey wrote:
Yeah that's one way to solve the problem. I think you're right that fundamentally the problem here is that what SECCOMP_RET_KILL wants is not really a signal. To the extent that it wants a signal, what it really wants is SIGKILL, and the problem here is the code trying to act like SIGKILL but call it SIGSYS. I assume the ship for fixing that sailed years ago though.
Yeah, this was IIRC, a specific design choice (to distinguish a seccomp KILL from a SIGKILL), as desired by the sandboxing folks, and instead of using two different signals (one for KILL and one for TRAP), both used SIGSYS, with the KILL variant being uncatchable.
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Kees Cook