From: Jeff Dike Kill a process that tries to branch into a stub and execute a system call. There are no security implications here - a system call in a stub is treated the same as a system call anywhere else. But if a process is trying to branch into a stub, either it is trying something nasty or it has gone haywire, so it's a good idea to get rid of it in either case. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton --- arch/um/os-Linux/skas/process.c | 3 +++ 1 file changed, 3 insertions(+) diff -puN arch/um/os-Linux/skas/process.c~uml-dont-allow-processes-to-call-into-stub arch/um/os-Linux/skas/process.c --- a/arch/um/os-Linux/skas/process.c~uml-dont-allow-processes-to-call-into-stub +++ a/arch/um/os-Linux/skas/process.c @@ -146,6 +146,9 @@ static void handle_trap(int pid, struct { int err, status; + if ((UPT_IP(regs) >= STUB_START) && (UPT_IP(regs) < STUB_END)) + fatal_sigsegv(); + /* Mark this as a syscall */ UPT_SYSCALL_NR(regs) = PT_SYSCALL_NR(regs->gp); _