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| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2020-02-17 18:17:01 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-02-18 15:34:20 +0100 |
| commit | 113e6b7e15e23dc45d5c66eb66bb91a627812e36 (patch) | |
| tree | 96d646cc04e8d070610f657cb716217268e2d3d9 /tools | |
| parent | f25975f42f2f8f2a01303054d6a70c7ceb1fcf54 (diff) | |
| download | linux-113e6b7e15e23dc45d5c66eb66bb91a627812e36.tar.bz2 | |
libbpf: Sanitise internal map names so they are not rejected by the kernel
The kernel only accepts map names with alphanumeric characters, underscores
and periods in their name. However, the auto-generated internal map names
used by libbpf takes their prefix from the user-supplied BPF object name,
which has no such restriction. This can lead to "Invalid argument" errors
when trying to load a BPF program using global variables.
Fix this by sanitising the map names, replacing any non-allowed characters
with underscores.
Fixes: d859900c4c56 ("bpf, libbpf: support global data/bss/rodata sections")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200217171701.215215-1-toke@redhat.com
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 514b1a524abb..7469c7dcc15e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -24,6 +24,7 @@ #include <endian.h> #include <fcntl.h> #include <errno.h> +#include <ctype.h> #include <asm/unistd.h> #include <linux/err.h> #include <linux/kernel.h> @@ -1283,7 +1284,7 @@ static size_t bpf_map_mmap_sz(const struct bpf_map *map) static char *internal_map_name(struct bpf_object *obj, enum libbpf_map_type type) { - char map_name[BPF_OBJ_NAME_LEN]; + char map_name[BPF_OBJ_NAME_LEN], *p; const char *sfx = libbpf_type_to_btf_name[type]; int sfx_len = max((size_t)7, strlen(sfx)); int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1, @@ -1292,6 +1293,11 @@ static char *internal_map_name(struct bpf_object *obj, snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name, sfx_len, libbpf_type_to_btf_name[type]); + /* sanitise map name to characters allowed by kernel */ + for (p = map_name; *p && p < map_name + sizeof(map_name); p++) + if (!isalnum(*p) && *p != '_' && *p != '.') + *p = '_'; + return strdup(map_name); } |