Commit b77ffb30 authored by Dan Carpenter's avatar Dan Carpenter Committed by Alexei Starovoitov
Browse files

libbpf: fix an snprintf() overflow check 



The snprintf() function returns the number of bytes it *would* have
copied if there were enough space.  So it can return > the
sizeof(gen->attach_target).

Fixes: 67234743 ("libbpf: Generate loader program out of BPF ELF file.")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/YtZ+oAySqIhFl6/J@kili


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent c5d22f4c

tools/lib/bpf/gen_loader.c

+1 −1
Original line number Diff line number Diff line
@@ -533,7 +533,7 @@ void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *attach_name, 
	gen->attach_kind = kind;

	ret = snprintf(gen->attach_target, sizeof(gen->attach_target), "%s%s",

		       prefix, attach_name);

	if (ret == sizeof(gen->attach_target))

	if (ret >= sizeof(gen->attach_target))

		gen->error = -ENOSPC;

}