From a8ecd38dce8daf6bf24de933efb72ae48acac7da Mon Sep 17 00:00:00 2001 From: Brian Vazquez Date: Sun, 19 Jan 2020 11:40:40 -0800 Subject: [PATCH] UPSTREAM: bpf: Fix memory leaks in generic update/delete batch ops Generic update/delete batch ops functions were using __bpf_copy_key without properly freeing the memory. Handle the memory allocation and copy_from_user separately. Fixes: aa2e93b8e58e ("bpf: Add generic support for update and delete batch ops") Reported-by: Dan Carpenter Change-Id: I42a98bfbb4e68c3ffb3dc958847ce8266ccb90f6 Signed-off-by: Brian Vazquez Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20200119194040.128369-1-brianvv@google.com --- kernel/bpf/syscall.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ff9a299f37d4..9650c3c5bc46 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1239,12 +1239,15 @@ int generic_map_delete_batch(struct bpf_map *map, if (!max_count) return 0; + key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + if (!key) + return -ENOMEM; + for (cp = 0; cp < max_count; cp++) { - key = __bpf_copy_key(keys + cp * map->key_size, map->key_size); - if (IS_ERR(key)) { - err = PTR_ERR(key); + err = -EFAULT; + if (copy_from_user(key, keys + cp * map->key_size, + map->key_size)) break; - } if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_delete_elem(map, key); @@ -1264,6 +1267,8 @@ int generic_map_delete_batch(struct bpf_map *map, } if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) err = -EFAULT; + + kfree(key); return err; } @@ -1294,18 +1299,21 @@ int generic_map_update_batch(struct bpf_map *map, if (!max_count) return 0; - value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); - if (!value) + key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN); + if (!key) return -ENOMEM; + value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + if (!value) { + kfree(key); + return -ENOMEM; + } + for (cp = 0; cp < max_count; cp++) { - key = __bpf_copy_key(keys + cp * map->key_size, map->key_size); - if (IS_ERR(key)) { - err = PTR_ERR(key); - break; - } err = -EFAULT; - if (copy_from_user(value, values + cp * value_size, value_size)) + if (copy_from_user(key, keys + cp * map->key_size, + map->key_size) || + copy_from_user(value, values + cp * value_size, value_size)) break; err = bpf_map_update_value(map, f, key, value,