On Tue, Mar 15, 2022 at 06:22:26PM -0500, Eric W. Biederman wrote: > > The signal a task should continue with after a ptrace stop is > inconsistently read, cleared, and sent. Solve this by reading and > clearing the signal to be sent in ptrace_stop. > > In an ideal world everything except ptrace_signal would share a common > implementation of continuing with the signal, so ptracers could count > on the signal they ask to continue with actually being delivered. For > now retain bug compatibility and just return with the signal number > the ptracer requested the code continue with. > > Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > --- > include/linux/ptrace.h | 12 ++++++------ > kernel/signal.c | 31 ++++++++++++++++++------------- > 2 files changed, 24 insertions(+), 19 deletions(-) > > diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h > index 3e6b46e2b7be..15b3d176b6b4 100644 > --- a/include/linux/ptrace.h > +++ b/include/linux/ptrace.h > @@ -60,7 +60,7 @@ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned > extern void ptrace_disable(struct task_struct *); > extern int ptrace_request(struct task_struct *child, long request, > unsigned long addr, unsigned long data); > -extern void ptrace_notify(int exit_code, unsigned long message); > +extern int ptrace_notify(int exit_code, unsigned long message); > [...] > -static void ptrace_stop(int exit_code, int why, int clear_code, > +static int ptrace_stop(int exit_code, int why, int clear_code, > unsigned long message, kernel_siginfo_t *info) > [...] > -static void ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) > +static int ptrace_do_notify(int signr, int exit_code, int why, unsigned long message) > [...] > -void ptrace_notify(int exit_code, unsigned long message) > +int ptrace_notify(int exit_code, unsigned long message) Just for robustness, how about marking the functions that have switched from void to int return as __must_check (or at least just ptrace_notify)? With that and the style nit Oleg already mentioned, yeah, this looks good too. Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> -- Kees Cook
