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-rw-r--r--kernel/bpf/inode.c7
-rw-r--r--kernel/bpf/syscall.c24
-rw-r--r--kernel/bpf/verifier.c11
3 files changed, 31 insertions, 11 deletions
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index f2ece3c174a5..8f94ca1860cf 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -31,10 +31,10 @@ static void *bpf_any_get(void *raw, enum bpf_type type)
{
switch (type) {
case BPF_TYPE_PROG:
- atomic_inc(&((struct bpf_prog *)raw)->aux->refcnt);
+ raw = bpf_prog_inc(raw);
break;
case BPF_TYPE_MAP:
- bpf_map_inc(raw, true);
+ raw = bpf_map_inc(raw, true);
break;
default:
WARN_ON_ONCE(1);
@@ -297,7 +297,8 @@ static void *bpf_obj_do_get(const struct filename *pathname,
goto out;
raw = bpf_any_get(inode->i_private, *type);
- touch_atime(&path);
+ if (!IS_ERR(raw))
+ touch_atime(&path);
path_put(&path);
return raw;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index adc5e4bd74f8..cf5e9f7ad13a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -218,11 +218,18 @@ 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)
@@ -234,7 +241,7 @@ 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;
@@ -658,6 +665,15 @@ 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()
*/
@@ -670,7 +686,7 @@ 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;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index db2574e7b8b0..89bcaa0966da 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2049,15 +2049,18 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
return -E2BIG;
}
- /* remember this map */
- env->used_maps[env->used_map_cnt++] = map;
-
/* hold the map. If the program is rejected by verifier,
* the map will be released by release_maps() or it
* will be used by the valid program until it's unloaded
* and all maps are released in free_bpf_prog_info()
*/
- bpf_map_inc(map, false);
+ map = bpf_map_inc(map, false);
+ if (IS_ERR(map)) {
+ fdput(f);
+ return PTR_ERR(map);
+ }
+ env->used_maps[env->used_map_cnt++] = map;
+
fdput(f);
next_insn:
insn++;