| Message ID | 20191023154038.24075-1-kpsingh@chromium.org |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf-next,v2] libbpf: Fix strncat bounds error in libbpf_prog_type_by_name | expand |
On Wed, Oct 23, 2019 at 8:40 AM KP Singh <kpsingh@chromium.org> wrote: > > From: KP Singh <kpsingh@google.com> > > On compiling samples with this change, one gets an error: > > error: ‘strncat’ specified bound 118 equals destination size > [-Werror=stringop-truncation] > > strncat(dst, name + section_names[i].len, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name)); > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > strncat requires the destination to have enough space for the > terminating null byte. > > Fixes: f75a697e09137 ("libbpf: Auto-detect btf_id of BTF-based raw_tracepoint") > Signed-off-by: KP Singh <kpsingh@google.com> Applied. Thanks
On Wed, Oct 23, 2019 at 9:06 PM KP Singh <kpsingh@chromium.org> wrote: > > From: KP Singh <kpsingh@google.com> > > On compiling samples with this change, one gets an error: > > error: ‘strncat’ specified bound 118 equals destination size > [-Werror=stringop-truncation] > > strncat(dst, name + section_names[i].len, > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name)); > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > strncat requires the destination to have enough space for the > terminating null byte. > > Fixes: f75a697e09137 ("libbpf: Auto-detect btf_id of BTF-based raw_tracepoint") > Signed-off-by: KP Singh <kpsingh@google.com> > --- Acked-by: Andrii Nakryiko <andriin@fb.com> > tools/lib/bpf/libbpf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 290684b504b7..dc7d493a7d3d 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -4693,7 +4693,7 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, > } > /* prepend "btf_trace_" prefix per kernel convention */ > strncat(dst, name + section_names[i].len, > - sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name)); > + sizeof(raw_tp_btf_name) - sizeof("btf_trace_")); > ret = btf__find_by_name(btf, raw_tp_btf_name); > btf__free(btf); > if (ret <= 0) { > -- > 2.20.1 >
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 290684b504b7..dc7d493a7d3d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4693,7 +4693,7 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, } /* prepend "btf_trace_" prefix per kernel convention */ strncat(dst, name + section_names[i].len, - sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name)); + sizeof(raw_tp_btf_name) - sizeof("btf_trace_")); ret = btf__find_by_name(btf, raw_tp_btf_name); btf__free(btf); if (ret <= 0) {