diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2020-09-17 15:44:53 +0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-09-21 21:20:17 +0200 |
| commit | 31f23a6a181c81543b10a1a9056b0e6c7ef1c747 (patch) | |
| tree | e275566fe13c8fdd63f4b6206173f2e9692a5844 | |
| parent | 70b971118e074d5042715587953f27929e99117a (diff) | |
bpf: Fix potential call bpf_link_free() in atomic context
The in_atomic() macro cannot always detect atomic context, in particular,
it cannot know about held spinlocks in non-preemptible kernels. Although,
there is no user call bpf_link_put() with holding spinlock now, be on the
safe side, so we can avoid this in the future.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200917074453.20621-1-songmuchun@bytedance.com
| -rw-r--r-- | kernel/bpf/syscall.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 2ce32cad5c8e..ec68d3a23a2b 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2345,12 +2345,8 @@ void bpf_link_put(struct bpf_link *link) if (!atomic64_dec_and_test(&link->refcnt)) return; - if (in_atomic()) { - INIT_WORK(&link->work, bpf_link_put_deferred); - schedule_work(&link->work); - } else { - bpf_link_free(link); - } + INIT_WORK(&link->work, bpf_link_put_deferred); + schedule_work(&link->work); } static int bpf_link_release(struct inode *inode, struct file *filp) |