From 92274e24b01b331ef7a4227135933e6163fe94aa Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 28 Oct 2021 12:04:58 +0530 Subject: [PATCH] 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: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.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(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 0c628c3..7e4c558 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -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)); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 73e1e70..742d1a3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -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); diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c index cd8c703..68f2dbf 100644 --- 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; diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c index ce0800e..f677dcc 100644 --- a/tools/lib/bpf/linker.c +++ b/tools/lib/bpf/linker.c @@ -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); diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index a211169..81f8fbc 100644 --- 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_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; -- 2.7.4