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Diffstat (limited to 'kernel/kernel/bpf/syscall.c')
-rw-r--r--kernel/kernel/bpf/syscall.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/kernel/kernel/bpf/syscall.c b/kernel/kernel/bpf/syscall.c
index 3b39550d8..4e32cc94e 100644
--- a/kernel/kernel/bpf/syscall.c
+++ b/kernel/kernel/bpf/syscall.c
@@ -181,11 +181,18 @@ struct bpf_map *__bpf_map_get(struct fd f)
return f.file->private_data;
}
-void bpf_map_inc(struct bpf_map *map, bool uref)
+/* prog's and map's refcnt limit */
+#define BPF_MAX_REFCNT 32768
+
+struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
{
- atomic_inc(&map->refcnt);
+ if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
+ atomic_dec(&map->refcnt);
+ return ERR_PTR(-EBUSY);
+ }
if (uref)
atomic_inc(&map->usercnt);
+ return map;
}
struct bpf_map *bpf_map_get_with_uref(u32 ufd)
@@ -197,7 +204,7 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd)
if (IS_ERR(map))
return map;
- bpf_map_inc(map, true);
+ map = bpf_map_inc(map, true);
fdput(f);
return map;
@@ -580,6 +587,15 @@ static struct bpf_prog *__bpf_prog_get(struct fd f)
return f.file->private_data;
}
+struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
+{
+ if (atomic_inc_return(&prog->aux->refcnt) > BPF_MAX_REFCNT) {
+ atomic_dec(&prog->aux->refcnt);
+ return ERR_PTR(-EBUSY);
+ }
+ return prog;
+}
+
/* called by sockets/tracing/seccomp before attaching program to an event
* pairs with bpf_prog_put()
*/
@@ -592,7 +608,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd)
if (IS_ERR(prog))
return prog;
- atomic_inc(&prog->aux->refcnt);
+ prog = bpf_prog_inc(prog);
fdput(f);
return prog;