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| author | Ian Rogers <irogers@google.com> | 2022-09-01 23:26:45 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 14:25:20 +0300 |
| commit | 557600830515199bc4ec31ca53e17791e4100d91 (patch) | |
| tree | 6fbf92d8fda546d4191c64f84dcd6df1f5c18444 /tools | |
| parent | c823df067941898e3ee77bf632e0c9d110d7e5b2 (diff) | |
| download | linux-557600830515199bc4ec31ca53e17791e4100d91.tar.xz | |
selftests/xsk: Avoid use-after-free on ctx
[ Upstream commit af515a5587b8f45f19e11657746e0c89411b0380 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/lib/bpf/xsk.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index e8745f646371..fa1f8faf7dfe 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -930,13 +930,13 @@ 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); } + xsk_put_ctx(ctx, true); + err = xsk_get_mmap_offsets(xsk->fd, &off); if (!err) { if (xsk->rx) { |