From 9cf309c56f7910a81fbe053b6f11c3b1f0987b12 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Thu, 3 Dec 2020 10:33:06 +0100 Subject: [PATCH] libbpf: Sanitise map names before pinning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When we added sanitising of map names before loading programs to libbpf, we still allowed periods in the name. While the kernel will accept these for the map names themselves, they are not allowed in file names when pinning maps. This means that bpf_object__pin_maps() will fail if called on an object that contains internal maps (such as sections .rodata). Fix this by replacing periods with underscores when constructing map pin paths. This only affects the paths generated by libbpf when bpf_object__pin_maps() is called with a path argument. Any pin paths set by bpf_map__set_pin_path() are unaffected, and it will still be up to the caller to avoid invalid characters in those. Fixes: 113e6b7e15e2 ("libbpf: Sanitise internal map names so they are not rejected by the kernel") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20201203093306.107676-1-toke@redhat.com --- tools/lib/bpf/libbpf.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index d6f45538444d..b2e16efabde0 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7659,6 +7659,16 @@ bool bpf_map__is_pinned(const struct bpf_map *map) return map->pinned; } +static void sanitize_pin_path(char *s) +{ + /* bpffs disallows periods in path names */ + while (*s) { + if (*s == '.') + *s = '_'; + s++; + } +} + int bpf_object__pin_maps(struct bpf_object *obj, const char *path) { struct bpf_map *map; @@ -7688,6 +7698,7 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path) err = -ENAMETOOLONG; goto err_unpin_maps; } + sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { continue; @@ -7732,6 +7743,7 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path) return -EINVAL; else if (len >= PATH_MAX) return -ENAMETOOLONG; + sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { continue;