signal/x86: In emulate_vsyscall force a signal instead of calling do_exit

commit 695dd0d634 upstream.

Directly calling do_exit with a signal number has the problem that
all of the side effects of the signal don't happen, such as
killing all of the threads of a process instead of just the
calling thread.

So replace do_exit(SIGSYS) with force_fatal_sig(SIGSYS) which
causes the signal handling to take it's normal path and work
as expected.

Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20211020174406.17889-17-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Thomas Backlund <tmb@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric W. Biederman 2021-10-20 12:44:03 -05:00 committed by Greg Kroah-Hartman
parent 3c4d5a38ca
commit 3e61002d05

View file

@ -226,7 +226,8 @@ bool emulate_vsyscall(unsigned long error_code,
if ((!tmp && regs->orig_ax != syscall_nr) || regs->ip != address) {
warn_bad_vsyscall(KERN_DEBUG, regs,
"seccomp tried to change syscall nr or ip");
do_exit(SIGSYS);
force_fatal_sig(SIGSYS);
return true;
}
regs->orig_ax = -1;
if (tmp)