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authorSong Liu <song@kernel.org>2022-03-02 09:51:26 -0800
committerAlexei Starovoitov <ast@kernel.org>2022-03-02 13:24:37 -0800
commit676b2daabaf9a993db0e02a5ce79b984aaa0388b (patch)
tree81b456d3fc63e54aaefe5a49187a8053474abfc6 /kernel/bpf/core.c
parenteed1fcee556fd8569afe94178b0c2784a5a6b717 (diff)
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/core.c')
-rw-r--r--kernel/bpf/core.c9
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);