6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peilin Ye [ Upstream commit 66faaea94e1a8e8197d98de6e9d07591970837d6 ] Factor out atomic_ptr_type_ok() as a helper function to be used later. Signed-off-by: Peilin Ye Link: https://lore.kernel.org/r/e5ef8b3116f3fffce78117a14060ddce05eba52a.1740978603.git.yepeilin@google.com Signed-off-by: Alexei Starovoitov Stable-dep-of: 179ee84a8911 ("bpf: Fix incorrect pruning due to atomic fetch precision tracking") Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4978c1d68bd98..1f5c8b5b74ffb 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5986,6 +5986,26 @@ static bool is_arena_reg(struct bpf_verifier_env *env, int regno) return reg->type == PTR_TO_ARENA; } +/* Return false if @regno contains a pointer whose type isn't supported for + * atomic instruction @insn. + */ +static bool atomic_ptr_type_ok(struct bpf_verifier_env *env, int regno, + struct bpf_insn *insn) +{ + if (is_ctx_reg(env, regno)) + return false; + if (is_pkt_reg(env, regno)) + return false; + if (is_flow_key_reg(env, regno)) + return false; + if (is_sk_reg(env, regno)) + return false; + if (is_arena_reg(env, regno)) + return bpf_jit_supports_insn(insn, true); + + return true; +} + static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { #ifdef CONFIG_NET [PTR_TO_SOCKET] = &btf_sock_ids[BTF_SOCK_TYPE_SOCK], @@ -7439,11 +7459,7 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i return -EACCES; } - if (is_ctx_reg(env, insn->dst_reg) || - is_pkt_reg(env, insn->dst_reg) || - is_flow_key_reg(env, insn->dst_reg) || - is_sk_reg(env, insn->dst_reg) || - (is_arena_reg(env, insn->dst_reg) && !bpf_jit_supports_insn(insn, true))) { + if (!atomic_ptr_type_ok(env, insn->dst_reg, insn)) { verbose(env, "BPF_ATOMIC stores into R%d %s is not allowed\n", insn->dst_reg, reg_type_str(env, reg_state(env, insn->dst_reg)->type)); -- 2.53.0