From f919e7fee7097e06a8fac9d25b1fd0a0bc5aadbb Mon Sep 17 00:00:00 2001 From: Xu Kuohai Date: Tue, 19 Oct 2021 03:29:34 +0000 Subject: [PATCH] UPSTREAM: bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch() 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") Change-Id: I765bf0a26423c9597719c0984c2b7659f7a98993 Signed-off-by: Xu Kuohai Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211019032934.1210517-1-xukuohai@huawei.com Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/syscall.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ef3117145b5a..174f2a085eb1 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1306,12 +1306,11 @@ int generic_map_update_batch(struct bpf_map *map, 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; @@ -1336,6 +1335,7 @@ int generic_map_update_batch(struct bpf_map *map, 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, @@ -1355,6 +1355,7 @@ int generic_map_update_batch(struct bpf_map *map, kfree(value); kfree(key); + fdput(f); return err; }