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| author | Song Liu <song@kernel.org> | 2022-03-02 09:51:26 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-03-02 13:24:37 -0800 |
| commit | 676b2daabaf9a993db0e02a5ce79b984aaa0388b (patch) | |
| tree | 81b456d3fc63e54aaefe5a49187a8053474abfc6 /kernel/bpf | |
| parent | eed1fcee556fd8569afe94178b0c2784a5a6b717 (diff) | |
| download | lwn-676b2daabaf9a993db0e02a5ce79b984aaa0388b.tar.gz lwn-676b2daabaf9a993db0e02a5ce79b984aaa0388b.zip | |
bpf, x86: Set header->size properly before freeing it
On do_jit failure path, the header is freed by bpf_jit_binary_pack_free.
While bpf_jit_binary_pack_free doesn't require proper ro_header->size,
bpf_prog_pack_free still uses it. Set header->size in bpf_int_jit_compile
before calling bpf_jit_binary_pack_free.
Fixes: 1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
Fixes: 33c9805860e5 ("bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]")
Reported-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220302175126.247459-3-song@kernel.org
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index ebb0193d07f0..ab630f773ec1 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1112,13 +1112,16 @@ int bpf_jit_binary_pack_finalize(struct bpf_prog *prog, * 1) when the program is freed after; * 2) when the JIT engine fails (before bpf_jit_binary_pack_finalize). * For case 2), we need to free both the RO memory and the RW buffer. - * Also, ro_header->size in 2) is not properly set yet, so rw_header->size - * is used for uncharge. + * + * bpf_jit_binary_pack_free requires proper ro_header->size. However, + * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size + * must be set with either bpf_jit_binary_pack_finalize (normal path) or + * bpf_arch_text_copy (when jit fails). */ void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header, struct bpf_binary_header *rw_header) { - u32 size = rw_header ? rw_header->size : ro_header->size; + u32 size = ro_header->size; bpf_prog_pack_free(ro_header); kvfree(rw_header); |