diff options
| author | Ian Rogers <irogers@google.com> | 2022-09-01 23:26:45 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-09-02 16:57:18 +0300 |
| commit | af515a5587b8f45f19e11657746e0c89411b0380 (patch) | |
| tree | cbf2995ac174c0303f65551e312734c3cf1e1219 /tools/testing/selftests | |
| parent | afef88e65554c3e8691513b8350d6445e292560e (diff) | |
| download | linux-af515a5587b8f45f19e11657746e0c89411b0380.tar.xz | |
selftests/xsk: Avoid use-after-free on ctx
The put lowers the reference count to 0 and frees ctx, reading it
afterwards is invalid. Move the put after the uses and determine the
last use by the reference count being 1.
Fixes: 39e940d4abfa ("selftests/xsk: Destroy BPF resources only when ctx refcount drops to 0")
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220901202645.1463552-1-irogers@google.com
Diffstat (limited to 'tools/testing/selftests')
| -rw-r--r-- | tools/testing/selftests/bpf/xsk.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/testing/selftests/bpf/xsk.c b/tools/testing/selftests/bpf/xsk.c index f2721a4ae7c5..0b3ff49c740d 100644 --- a/tools/testing/selftests/bpf/xsk.c +++ b/tools/testing/selftests/bpf/xsk.c @@ -1237,15 +1237,15 @@ void xsk_socket__delete(struct xsk_socket *xsk) ctx = xsk->ctx; umem = ctx->umem; - xsk_put_ctx(ctx, true); - - if (!ctx->refcount) { + if (ctx->refcount == 1) { xsk_delete_bpf_maps(xsk); close(ctx->prog_fd); if (ctx->has_bpf_link) close(ctx->link_fd); } + xsk_put_ctx(ctx, true); + err = xsk_get_mmap_offsets(xsk->fd, &off); if (!err) { if (xsk->rx) { |