diff options
| author |   Ian Rogers <irogers@google.com> | 2022-09-01 13:26:45 -0700 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2022-09-02 15:57:18 +0200 |
| commit | af515a5587b8f45f19e11657746e0c89411b0380 (patch) | |
| tree | cbf2995ac174c0303f65551e312734c3cf1e1219 /tools/testing/selftests/bpf | |
| parent | selftests/bpf: Store BPF object files with .bpf.o extension (diff) | |
| download | linux-dev-af515a5587b8f45f19e11657746e0c89411b0380.tar.xz linux-dev-af515a5587b8f45f19e11657746e0c89411b0380.zip | |
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/bpf')
| -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) { |