Kees Cook <keescook@xxxxxxxxxxxx> writes: > On Thu, Jun 24, 2021 at 01:59:55PM -0500, Eric W. Biederman wrote: >> >> Factor out force_sig_seccomp from the seccomp signal generation and >> place it in kernel/signal.c. The function force_sig_seccomp takes a >> paramter force_coredump to indicate that the sigaction field should be >> reset to SIGDFL so that a coredump will be generated when the signal >> is delivered. > > Ah! This is the part I missed when I was originally trying to figure > out the coredump stuff. It's the need for setting a default handler > (i.e. doing a coredump)? Yes. If we don't force the handler to SIG_DFL someone might catch SIGSYS. >> force_sig_seccomp is then used to replace both seccomp_send_sigsys >> and seccomp_init_siginfo. >> >> force_sig_info_to_task gains an extra parameter to force using >> the default signal action. >> >> With this change seccomp is no longer a special case and there >> becomes exactly one place do_coredump is called from. > > Looks good to me. This may benefit from force_sig_seccomp() to be wrapped > in an #ifdef CONFIG_SECCOMP. At which point Linus will probably be grumpy with me for introducing #ifdefs. I suspect seccomp at this point is sufficiently common that is probably more productive to figure out how to remove #ifdef CONFIG_SECCOMP. > (This patch reminds me that the seccomp self tests don't check for core > dumps...) This patch is slightly wrong in that it kept the call to do_group_exit when it can never be reached. Eric