From: Xu Kuohai xukuohai@huawei.com
commit fda7a38714f40b635f5502ec4855602c6b33dad2 upstream.
1. The ufd in generic_map_update_batch() should be read from batch.map_fd; 2. A call to fdget() should be followed by a symmetric call to fdput().
Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops") Signed-off-by: Xu Kuohai xukuohai@huawei.com Signed-off-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/bpf/20211019032934.1210517-1-xukuohai@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/syscall.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1333,12 +1333,11 @@ int generic_map_update_batch(struct bpf_ void __user *values = u64_to_user_ptr(attr->batch.values); void __user *keys = u64_to_user_ptr(attr->batch.keys); u32 value_size, cp, max_count; - int ufd = attr->map_fd; + int ufd = attr->batch.map_fd; void *key, *value; struct fd f; int err = 0;
- f = fdget(ufd); if (attr->batch.elem_flags & ~BPF_F_LOCK) return -EINVAL;
@@ -1363,6 +1362,7 @@ int generic_map_update_batch(struct bpf_ return -ENOMEM; }
+ f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */ for (cp = 0; cp < max_count; cp++) { err = -EFAULT; if (copy_from_user(key, keys + cp * map->key_size, @@ -1382,6 +1382,7 @@ int generic_map_update_batch(struct bpf_
kfree(value); kfree(key); + fdput(f); return err; }