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| author | Shung-Hsi Yu <shung-hsi.yu@suse.com> | 2022-03-07 13:29:18 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-03-08 15:36:45 +0100 |
| commit | 44e9a741cad824f45112b79c21d88c201d5aec13 (patch) | |
| tree | 03e6959f89fc523b68b0fc98f19a81cdaa6cfafd /kernel | |
| parent | e878ae2d1df5de4ea36e6d96c7d3ebe789aab9a5 (diff) | |
| download | linux-stable-44e9a741cad824f45112b79c21d88c201d5aec13.tar.gz linux-stable-44e9a741cad824f45112b79c21d88c201d5aec13.tar.bz2 linux-stable-44e9a741cad824f45112b79c21d88c201d5aec13.zip | |
bpf: Determine buf_info inside check_buffer_access()
Instead of determining buf_info string in the caller of check_buffer_access(),
we can determine whether the register type is read-only through
type_is_rdonly_mem() helper inside check_buffer_access() and construct
buf_info, making the code slightly cleaner.
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/YiWYLnAkEZXBP/gH@syu-laptop
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ec3a7b6c9515..e34264200e09 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4062,9 +4062,9 @@ static int check_buffer_access(struct bpf_verifier_env *env, const struct bpf_reg_state *reg, int regno, int off, int size, bool zero_size_allowed, - const char *buf_info, u32 *max_access) { + const char *buf_info = type_is_rdonly_mem(reg->type) ? "rdonly" : "rdwr"; int err; err = __check_buffer_access(env, buf_info, reg, regno, off, size); @@ -4576,7 +4576,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn value_regno); } else if (base_type(reg->type) == PTR_TO_BUF) { bool rdonly_mem = type_is_rdonly_mem(reg->type); - const char *buf_info; u32 *max_access; if (rdonly_mem) { @@ -4585,15 +4584,13 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn regno, reg_type_str(env, reg->type)); return -EACCES; } - buf_info = "rdonly"; max_access = &env->prog->aux->max_rdonly_access; } else { - buf_info = "rdwr"; max_access = &env->prog->aux->max_rdwr_access; } err = check_buffer_access(env, reg, regno, off, size, false, - buf_info, max_access); + max_access); if (!err && value_regno >= 0 && (rdonly_mem || t == BPF_READ)) mark_reg_unknown(env, regs, value_regno); @@ -4856,7 +4853,6 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, struct bpf_call_arg_meta *meta) { struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; - const char *buf_info; u32 *max_access; switch (base_type(reg->type)) { @@ -4883,15 +4879,13 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, if (meta && meta->raw_mode) return -EACCES; - buf_info = "rdonly"; max_access = &env->prog->aux->max_rdonly_access; } else { - buf_info = "rdwr"; max_access = &env->prog->aux->max_rdwr_access; } return check_buffer_access(env, reg, regno, reg->off, access_size, zero_size_allowed, - buf_info, max_access); + max_access); case PTR_TO_STACK: return check_stack_range_initialized( env, |