diff options
| author | Lorenz Bauer <lmb@cloudflare.com> | 2021-10-14 15:25:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 14:03:42 +0100 |
| commit | b92ac0a9ca8f27076c2096cae0896b94aaa4a6ac (patch) | |
| tree | e95c2075dcb0fc35fb4a685c264d2c2d857d71e9 /kernel | |
| parent | a3564fb7b0bf11d941d57c87b0f38a656a997860 (diff) | |
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 <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -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 72e4bf0ee546..d3a1f25f8ec2 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -528,6 +528,7 @@ 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) @@ -821,7 +822,8 @@ 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; } |