leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

libbpf: Don't call libc APIs with NULL pointers

Browse Source 
Sanitizer complains about qsort(), bsearch(), and memcpy() being called
with NULL pointer. This can only happen when the associated number of
elements is zero, so no harm should be done. But still prevent this from
happening to keep sanitizer runs clean from extra noise.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124002325.1737739-5-andrii@kernel.org
This commit is contained in:
Andrii Nakryiko 2021-11-23 16:23:16 -08:00 committed by Daniel Borkmann
parent 401891a9de
commit 2a6a9bf261
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
tools/lib/bpf/libbpf.c
View File

@ -3369,7 +3369,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
/* sort BPF programs by section name and in-section instruction offset
* for faster search */
qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
if (obj->nr_programs)
qsort(obj->programs, obj->nr_programs, sizeof(*obj->programs), cmp_progs);
return bpf_object__init_btf(obj, btf_data, btf_ext_data);
}
@ -5823,6 +5824,8 @@ static int cmp_relo_by_insn_idx(const void *key, const void *elem)
static struct reloc_desc *find_prog_insn_relo(const struct bpf_program *prog, size_t insn_idx)
{
if (!prog->nr_reloc)
return NULL;
return bsearch(&insn_idx, prog->reloc_desc, prog->nr_reloc,
sizeof(*prog->reloc_desc), cmp_relo_by_insn_idx);
}
@ -5838,8 +5841,9 @@ static int append_subprog_relos(struct bpf_program *main_prog, struct bpf_progra
relos = libbpf_reallocarray(main_prog->reloc_desc, new_cnt, sizeof(*relos));
if (!relos)
return -ENOMEM;
memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
sizeof(*relos) * subprog->nr_reloc);
if (subprog->nr_reloc)
memcpy(relos + main_prog->nr_reloc, subprog->reloc_desc,
sizeof(*relos) * subprog->nr_reloc);
for (i = main_prog->nr_reloc; i < new_cnt; i++)
relos[i].insn_idx += subprog->sub_insn_off;