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| author |   Yonghong Song <yhs@fb.com> | 2019-04-09 17:37:41 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2019-04-10 09:46:51 +0200 |
| commit | 69a0f9ecef22131982ba328e6b74ebb082bc0992 (patch) | |
| tree | 75665c934bb3b1449a290394d33f2b435d16b6f9 /tools/lib | |
| parent | Merge branch 'support-global-data' (diff) | |
| download | linux-dev-69a0f9ecef22131982ba328e6b74ebb082bc0992.tar.xz linux-dev-69a0f9ecef22131982ba328e6b74ebb082bc0992.zip | |
bpf, bpftool: fix a few ubsan warnings
The issue is reported at https://github.com/libbpf/libbpf/issues/28.
Basically, per C standard, for
void *memcpy(void *dest, const void *src, size_t n)
if "dest" or "src" is NULL, regardless of whether "n" is 0 or not,
the result of memcpy is undefined. clang ubsan reported three such
instances in bpf.c with the following pattern:
memcpy(dest, 0, 0).
Although in practice, no known compiler will cause issues when
copy size is 0. Let us still fix the issue to silence ubsan
warnings.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/bpf.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index c039094ad3aa..dababce68f0b 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -79,7 +79,6 @@ static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size) int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) { - __u32 name_len = create_attr->name ? strlen(create_attr->name) : 0; union bpf_attr attr; memset(&attr, '\0', sizeof(attr)); @@ -89,8 +88,9 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) attr.value_size = create_attr->value_size; attr.max_entries = create_attr->max_entries; attr.map_flags = create_attr->map_flags; - memcpy(attr.map_name, create_attr->name, - min(name_len, BPF_OBJ_NAME_LEN - 1)); + if (create_attr->name) + memcpy(attr.map_name, create_attr->name, + min(strlen(create_attr->name), BPF_OBJ_NAME_LEN - 1)); attr.numa_node = create_attr->numa_node; attr.btf_fd = create_attr->btf_fd; attr.btf_key_type_id = create_attr->btf_key_type_id; @@ -155,7 +155,6 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, int key_size, int inner_map_fd, int max_entries, __u32 map_flags, int node) { - __u32 name_len = name ? strlen(name) : 0; union bpf_attr attr; memset(&attr, '\0', sizeof(attr)); @@ -166,7 +165,9 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, attr.inner_map_fd = inner_map_fd; attr.max_entries = max_entries; attr.map_flags = map_flags; - memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1)); + if (name) + memcpy(attr.map_name, name, + min(strlen(name), BPF_OBJ_NAME_LEN - 1)); if (node >= 0) { attr.map_flags |= BPF_F_NUMA_NODE; @@ -216,7 +217,6 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, void *finfo = NULL, *linfo = NULL; union bpf_attr attr; __u32 log_level; - __u32 name_len; int fd; if (!load_attr || !log_buf != !log_buf_sz) @@ -226,8 +226,6 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, if (log_level > (4 | 2 | 1) || (log_level && !log_buf)) return -EINVAL; - name_len = load_attr->name ? strlen(load_attr->name) : 0; - memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; @@ -253,8 +251,9 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.line_info_rec_size = load_attr->line_info_rec_size; attr.line_info_cnt = load_attr->line_info_cnt; attr.line_info = ptr_to_u64(load_attr->line_info); - memcpy(attr.prog_name, load_attr->name, - min(name_len, BPF_OBJ_NAME_LEN - 1)); + if (load_attr->name) + memcpy(attr.prog_name, load_attr->name, + min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1)); fd = sys_bpf_prog_load(&attr, sizeof(attr)); if (fd >= 0) |