Messages in this thread | | | Date | Fri, 30 Nov 2018 11:17:51 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH v8 1/2] seccomp: add a return code to trap to userspace |
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On 11/29, Tycho Andersen wrote: > > /* > * These should never be seen by user programs. To return one of ERESTART* > * codes, signal_pending() MUST be set. Note that ptrace can observe these > * at syscall exit tracing, but they will never be left for the debugged user > * process to see. > */ > #define ERESTARTSYS 512 > > So basically, if you respond with -ERESTARTSYS with no signal pending, you'll > leak it to userspace.
Yes,
> It turns out this is already possible with > SECCOMP_RET_TRAP (and probably ptrace alone,
Yes,
> The question is: do we care?
I think we do not care, debugger can do anything with the tracee.
Oleg.
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