From 06e5c999f10269a532304e89a6adb2fbfeb0593c Mon Sep 17 00:00:00 2001 From: Hou Tao Date: Fri, 8 Dec 2023 18:23:53 +0800 Subject: bpf: Set uattr->batch.count as zero before batched update or deletion 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 Link: https://lore.kernel.org/r/20231208102355.2628918-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index dd641475b65f..06320d9abf33 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1731,6 +1731,9 @@ 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; @@ -1787,6 +1790,9 @@ 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; -- cgit v1.2.3