From c3494801cd1785e2c25f1a5735fa19ddcf9665da Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 3 Dec 2018 22:46:04 -0800 Subject: 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 Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Acked-by: Edward Cree Signed-off-by: Daniel Borkmann --- kernel/bpf/verifier.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6dd419550aba..751bb30b7c5c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -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(); -- cgit v1.2.3