Commit 92274e24 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

libbpf: Use O_CLOEXEC uniformly when opening fds 



There are some instances where we don't use O_CLOEXEC when opening an
fd, fix these up. Otherwise, it is possible that a parallel fork causes
these fds to leak into a child process on execve.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.com
parent 549a6323

tools/lib/bpf/btf.c

+1 −1
Original line number Diff line number Diff line
@@ -897,7 +897,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf, 
		return ERR_PTR(-LIBBPF_ERRNO__LIBELF);

	}



	fd = open(path, O_RDONLY);

	fd = open(path, O_RDONLY | O_CLOEXEC);

	if (fd < 0) {

		err = -errno;

		pr_warn("failed to open %s: %s\n", path, strerror(errno));

tools/lib/bpf/libbpf.c

+3 −3
Original line number Diff line number Diff line
@@ -1232,7 +1232,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) 
		 */

		elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz);

	} else {

		obj->efile.fd = open(obj->path, O_RDONLY);

		obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC);

		if (obj->efile.fd < 0) {

			char errmsg[STRERR_BUFSIZE], *cp;
@@ -9615,7 +9615,7 @@ static int append_to_file(const char *file, const char *fmt, ...) 
	int fd, n, err = 0;

	va_list ap;



	fd = open(file, O_WRONLY | O_APPEND, 0);

	fd = open(file, O_WRONLY | O_APPEND | O_CLOEXEC, 0);

	if (fd < 0)

		return -errno;
@@ -11260,7 +11260,7 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz) 
	int fd, err = 0, len;

	char buf[128];



	fd = open(fcpu, O_RDONLY);

	fd = open(fcpu, O_RDONLY | O_CLOEXEC);

	if (fd < 0) {

		err = -errno;

		pr_warn("Failed to open cpu mask file %s: %d\n", fcpu, err);

tools/lib/bpf/libbpf_probes.c

+1 −1
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ static int get_vendor_id(int ifindex) 


	snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname);



	fd = open(path, O_RDONLY);

	fd = open(path, O_RDONLY | O_CLOEXEC);

	if (fd < 0)

		return -1;

tools/lib/bpf/linker.c

+2 −2
Original line number Diff line number Diff line
@@ -301,7 +301,7 @@ static int init_output_elf(struct bpf_linker *linker, const char *file) 
	if (!linker->filename)

		return -ENOMEM;



	linker->fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, 0644);

	linker->fd = open(file, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);

	if (linker->fd < 0) {

		err = -errno;

		pr_warn("failed to create '%s': %d\n", file, err);
@@ -556,7 +556,7 @@ static int linker_load_obj_file(struct bpf_linker *linker, const char *filename, 


	obj->filename = filename;



	obj->fd = open(filename, O_RDONLY);

	obj->fd = open(filename, O_RDONLY | O_CLOEXEC);

	if (obj->fd < 0) {

		err = -errno;

		pr_warn("failed to open file '%s': %d\n", filename, err);

tools/lib/bpf/xsk.c

+3 −3
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, 
	if (!umem)

		return -ENOMEM;



	umem->fd = socket(AF_XDP, SOCK_RAW, 0);

	umem->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);

	if (umem->fd < 0) {

		err = -errno;

		goto out_umem_alloc;
@@ -549,7 +549,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk) 
	struct ifreq ifr = {};

	int fd, err, ret;



	fd = socket(AF_LOCAL, SOCK_DGRAM, 0);

	fd = socket(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0);

	if (fd < 0)

		return -errno;
@@ -1046,7 +1046,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, 
	}



	if (umem->refcount++ > 0) {

		xsk->fd = socket(AF_XDP, SOCK_RAW, 0);

		xsk->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);

		if (xsk->fd < 0) {

			err = -errno;

			goto out_xsk_alloc;