From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu, 28 Oct 2021 12:04:58 +0530
Subject: libbpf: Use O_CLOEXEC uniformly when opening fds
Patch-mainline: v5.16-rc1
Git-commit: 92274e24b01b331ef7a4227135933e6163fe94aa
References: jsc#PED-1377

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: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 tools/lib/bpf/btf.c           |    2 +-
 tools/lib/bpf/libbpf.c        |    6 +++---
 tools/lib/bpf/libbpf_probes.c |    2 +-
 tools/lib/bpf/linker.c        |    4 ++--
 tools/lib/bpf/xsk.c           |    6 +++---
 5 files changed, 10 insertions(+), 10 deletions(-)

--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -897,7 +897,7 @@ static struct btf *btf_parse_elf(const c
 		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));
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1232,7 +1232,7 @@ static int bpf_object__elf_init(struct b
 		 */
 		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;
 
@@ -9614,7 +9614,7 @@ static int append_to_file(const char *fi
 	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;
 
@@ -11245,7 +11245,7 @@ int parse_cpu_mask_file(const char *fcpu
 	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);
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -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;
 
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -301,7 +301,7 @@ static int init_output_elf(struct bpf_li
 	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 b
 
 	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);
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -300,7 +300,7 @@ int xsk_umem__create_v0_0_4(struct xsk_u
 	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
 	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
 	}
 
 	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;