Commit 8a98ae12 authored Sep 22, 2021 by Lorenz Bauer Committed by Daniel Borkmann Sep 28, 2021

bpf: Exempt CAP_BPF from checks against bpf_jit_limit



When introducing CAP_BPF, bpf_jit_charge_modmem() was not changed to treat
programs with CAP_BPF as privileged for the purpose of JIT memory allocation.
This means that a program without CAP_BPF can block a program with CAP_BPF
from loading a program.

Fix this by checking bpf_capable() in bpf_jit_charge_modmem().

Fixes: 2c78ee89 ("bpf: Implement CAP_BPF")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210922111153.19843-1-lmb@cloudflare.com

parent 37cb28ec

kernel/bpf/core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -827,7 +827,7 @@ int bpf_jit_charge_modmem(u32 pages)
		{
		if (atomic_long_add_return(pages, &bpf_jit_current) >
		(bpf_jit_limit >> PAGE_SHIFT)) {
		if (!capable(CAP_SYS_ADMIN)) {
		if (!bpf_capable()) {
		atomic_long_sub(pages, &bpf_jit_current);
		return -EPERM;
		}