diff options
| author | Hou Tao <hotforest@gmail.com> | 2022-02-02 14:01:58 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-02-02 13:17:49 +0100 |
| commit | 48f52cba8400016c2fc1bbef3e35464fc90ba4c1 (patch) | |
| tree | 284d9f6552a276acc56f3263694f5b23084fecca | |
| parent | b7892f7d5cb2b8187c603dd8ea3a7c44059ccfc2 (diff) | |
| download | bpf-pr/rb-vmap.tar.gz | |
bpf: use VM_MAP instead of VM_ALLOC for ringbufpr/rb-vmap
[ https://patchwork.kernel.org/project/netdevbpf/patch/20220202060158.6260-1-houtao1@huawei.com/ ]
After commit 2fd3fb0be1d1 ("kasan, vmalloc: unpoison VM_ALLOC pages
after mapping"), non-VM_ALLOC mappings will be marked as accessible
in __get_vm_area_node() when KASAN is enabled. But now the flag for
ringbuf area is VM_ALLOC, so KASAN will complain out-of-bound access
after vmap() returns. Because the ringbuf area is created by mapping
allocated pages, so use VM_MAP instead.
After the change, info in /proc/vmallocinfo also changes from
[start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmalloc user
to
[start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmap user
Reported-by: syzbot+5ad567a418794b9b5983@syzkaller.appspotmail.com
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | kernel/bpf/ringbuf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index 638d7fd7b37545..710ba9de12ce41 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -104,7 +104,7 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node) } rb = vmap(pages, nr_meta_pages + 2 * nr_data_pages, - VM_ALLOC | VM_USERMAP, PAGE_KERNEL); + VM_MAP | VM_USERMAP, PAGE_KERNEL); if (rb) { kmemleak_not_leak(pages); rb->pages = pages; |