From: Lorenz Bauer Date: Thu, 14 Oct 2021 14:25:53 +0000 (+0100) Subject: bpf: Prevent increasing bpf_jit_limit above max X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d7fe64cf671865b98dadb9c88db86fabfb4e5076;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git bpf: Prevent increasing bpf_jit_limit above max [ Upstream commit fadb7ff1a6c2c565af56b4aacdd086b067eed440 ] Restrict bpf_jit_limit to the maximum supported by the arch's JIT. Signed-off-by: Lorenz Bauer Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com Signed-off-by: Sasha Levin --- diff --git a/include/linux/filter.h b/include/linux/filter.h index f33f80ee9dc6..0ec7f787a9db 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -790,6 +790,7 @@ extern int bpf_jit_enable; extern int bpf_jit_harden; extern int bpf_jit_kallsyms; extern long bpf_jit_limit; +extern long bpf_jit_limit_max; typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index c733e749aa42..fec074c6231a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -295,6 +295,7 @@ int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); int bpf_jit_harden __read_mostly; int bpf_jit_kallsyms __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static __always_inline void bpf_get_prog_addr_region(const struct bpf_prog *prog, @@ -508,7 +509,8 @@ u64 __weak bpf_jit_alloc_exec_limit(void) static int __init bpf_jit_charge_init(void) { /* Only used as heuristic here to derive limit. */ - bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, + bpf_jit_limit_max = bpf_jit_alloc_exec_limit(); + bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 2, PAGE_SIZE), LONG_MAX); return 0; } diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 069e3c4fcc44..ac1a32d5cad3 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -410,7 +410,7 @@ static struct ctl_table net_core_table[] = { .mode = 0600, .proc_handler = proc_dolongvec_minmax_bpf_restricted, .extra1 = &long_one, - .extra2 = &long_max, + .extra2 = &bpf_jit_limit_max, }, #endif {