bpf: check pending signals while verifying programs

Malicious user space may try to force the verifier to use as much cpu
time and memory as possible. Hence check for pending signals
while verifying the program.
Note that suspend of sys_bpf(PROG_LOAD) syscall will lead to EAGAIN,
since the kernel has to release the resources used for program verification.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Alexei Starovoitov 2018-12-03 22:46:04 -08:00 committed by Daniel Borkmann
parent 025dceb0fa
commit c3494801cd

View File

@ -5148,6 +5148,9 @@ static int do_check(struct bpf_verifier_env *env)
goto process_bpf_exit;
}
if (signal_pending(current))
return -EAGAIN;
if (need_resched())
cond_resched();