From: Hou Tao <houtao1@xxxxxxxxxx>
generic_map_{delete,update}_batch() doesn't set uattr->batch.count as
zero before it tries to allocate memory for key. If the memory
allocation fails, the value of uattr->batch.count will be incorrect.
Fix it by setting uattr->batch.count as zero beore batched update or
deletion.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b711cc941664..efda2353a7d5 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1715,6 +1715,9 @@ int generic_map_delete_batch(struct bpf_map *map,
if (!max_count)
return 0;
+ if (put_user(0, &uattr->batch.count))
+ return -EFAULT;
+
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
@@ -1771,6 +1774,9 @@ int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
if (!max_count)
return 0;
+ if (put_user(0, &uattr->batch.count))
+ return -EFAULT;
+
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
--
2.29.2
