diff options
| author | Lorenz Bauer <lmb@cloudflare.com> | 2021-10-14 17:25:53 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-10-23 03:23:53 +0300 |
| commit | fadb7ff1a6c2c565af56b4aacdd086b067eed440 (patch) | |
| tree | 3e5cda8336b05541dd33b7888ba131c1bc910871 /kernel/bpf | |
| parent | 5d63ae908242f028bd10860cba98450d11c079b8 (diff) | |
| download | linux-fadb7ff1a6c2c565af56b4aacdd086b067eed440.tar.xz | |
bpf: Prevent increasing bpf_jit_limit above max
Restrict bpf_jit_limit to the maximum supported by the arch's JIT.
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index d6b7dfdd8066..c1e7eb3f1876 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -524,6 +524,7 @@ int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); int bpf_jit_harden __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static void bpf_prog_ksym_set_addr(struct bpf_prog *prog) @@ -817,7 +818,8 @@ 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; } |