Messages in this thread | | | From | "Bae, Chang Seok" <> | Subject | Re: [PATCH v8 5/6] x86/signal: Detect and prevent an alternate signal stack overflow | Date | Wed, 12 May 2021 18:48:11 +0000 |
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On May 11, 2021, at 11:36, Borislav Petkov <bp@alien8.de> wrote: > > I clumsily tried to register a SIGSEGV handler with > > act.sa_sigaction = my_sigsegv; > sigaction(SIGSEGV, &act, NULL); > > but that doesn't fire - task gets killed. Maybe I'm doing it wrong.
Since the altstack is already overflowed, perhaps set the flag like this -- not using it to get the handler:
act.sa_sigaction = my_sigsegv; + act.sa_flags = SA_SIGINFO; sigaction(SIGSEGV, &act, NULL);
FWIW, I think this is just a workaround for this case; in practice, altstack is rather a backup for normal stack corruption.
Thanks, Chang
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