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| author | Lorenz Bauer <lmb@cloudflare.com> | 2021-10-14 15:25:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-26 11:48:20 +0100 |
| commit | 045644540e75a9898a49003e91e24d609f1897b0 (patch) | |
| tree | f50dc6edecbe3da14d368732f38e36d5fd58ed73 /kernel | |
| parent | 524489b3409198f35b0202492a27b899946a5abc (diff) | |
| download | linux-stable-045644540e75a9898a49003e91e24d609f1897b0.tar.gz linux-stable-045644540e75a9898a49003e91e24d609f1897b0.tar.bz2 linux-stable-045644540e75a9898a49003e91e24d609f1897b0.zip | |
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 df2ebce927ec..3ce69c0276c0 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -212,6 +212,7 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); int bpf_jit_harden __read_mostly; long bpf_jit_limit __read_mostly; +long bpf_jit_limit_max __read_mostly; static atomic_long_t bpf_jit_current; @@ -231,7 +232,8 @@ 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; } |