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| author | Hou Tao <hotforest@gmail.com> | 2022-02-02 09:01:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-08 20:34:11 +0300 |
| commit | 5e457aeab52a5947619e1f18047f4d2f3212b3eb (patch) | |
| tree | f76f4b516a94ae28371f895841fdf2d03b6cf8cd /kernel | |
| parent | 62ab929a8f6bc7717fc26361c967d92924f4e297 (diff) | |
| download | linux-5e457aeab52a5947619e1f18047f4d2f3212b3eb.tar.xz | |
bpf: Use VM_MAP instead of VM_ALLOC for ringbuf
commit b293dcc473d22a62dc6d78de2b15e4f49515db56 upstream.
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
Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it")
Reported-by: syzbot+5ad567a418794b9b5983@syzkaller.appspotmail.com
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220202060158.6260-1-houtao1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -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 9e0c10c6892a..f1c51c45667d 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; |