tools: bpf: make use of reallocarray

reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation.  Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed.  Use feature
detection to probe for existence of reallocarray.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski 2018-07-10 14:43:05 -07:00 committed by Daniel Borkmann
parent 8d13406c02
commit 531b014e7a
10 changed files with 334 additions and 9 deletions

View file

@ -22,6 +22,7 @@
* License along with this program; if not, see <http://www.gnu.org/licenses>
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
@ -41,6 +42,7 @@
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/vfs.h>
#include <tools/libc_compat.h>
#include <libelf.h>
#include <gelf.h>
@ -321,7 +323,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
progs = obj->programs;
nr_progs = obj->nr_programs;
progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
if (!progs) {
/*
* In this case the original obj->programs
@ -822,8 +824,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
continue;
}
reloc = realloc(reloc,
sizeof(*obj->efile.reloc) * nr_reloc);
reloc = reallocarray(reloc, nr_reloc,
sizeof(*obj->efile.reloc));
if (!reloc) {
pr_warning("realloc failed\n");
err = -ENOMEM;
@ -1115,7 +1117,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
return -LIBBPF_ERRNO__RELOC;
}
new_cnt = prog->insns_cnt + text->insns_cnt;
new_insn = realloc(prog->insns, new_cnt * sizeof(*insn));
new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
if (!new_insn) {
pr_warning("oom in prog realloc\n");
return -ENOMEM;