Commit c3494801 authored Dec 03, 2018 by Alexei Starovoitov Committed by Daniel Borkmann Dec 04, 2018

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>

parent 025dceb0

kernel/bpf/verifier.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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();

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