From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 399E91EA65; Mon, 2 Jun 2025 14:48:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748875719; cv=none; b=VEm/mhV46NQzURiWGhhgnOY64qWFN5sCojhzREDMe8/GBWyBaHAu8wOqfWps2wHaS6zTufr+9MHNP99I4dUUe6ZqI+pNhdkNyOTyVKAwEiHXVDjuLgvsnBmTAqcaDRQWzluO47IIY20gbkuLqP6lu5O+2BKxh58wW5W0VyBOalw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748875719; c=relaxed/simple; bh=v+wxQsAE08UjMMlFuKFPqTvMg5VcINGuqD1VsDO202g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LkiY3JvaMRULE7eq+L+i2gRVKom7IXdnBA6k+GznDoXkgED0G8hEongss23LYhGeoBo1ukk2rN4Xy3PMCPTGP6jI1dp4HbUvFu5SUaGG5IOED9YtKfv9yqYOIyDGl8HzU7EJ2Wi/efTNkEzL5FUs193bk0slMZtBauW7yHZZ4q4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iiPPI5X/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="iiPPI5X/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74335C4CEEB; Mon, 2 Jun 2025 14:48:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748875719; bh=v+wxQsAE08UjMMlFuKFPqTvMg5VcINGuqD1VsDO202g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iiPPI5X/zBD+PspFTKzY5qNxTlc5Bh68d6V1djgxi+HSgyEgNTf6bAbvOyCiuYJQ7 YbrfT/kcdELacLzPsUef7N696nP3ON/SVTH2aJGsGLkO6fYrFxB+3+3yYoJnWgR5WY dtlgYbtf7qwzvjEJWwb4x5zxMi0KPxzDSElefARo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Viktor Malik , Andrii Nakryiko , Quentin Monnet , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.10 221/270] bpftool: Fix readlink usage in get_fd_type Date: Mon, 2 Jun 2025 15:48:26 +0200 Message-ID: <20250602134316.215123156@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134307.195171844@linuxfoundation.org> References: <20250602134307.195171844@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Viktor Malik [ Upstream commit 0053f7d39d491b6138d7c526876d13885cbb65f1 ] The `readlink(path, buf, sizeof(buf))` call reads at most sizeof(buf) bytes and *does not* append null-terminator to buf. With respect to that, fix two pieces in get_fd_type: 1. Change the truncation check to contain sizeof(buf) rather than sizeof(path). 2. Append null-terminator to buf. Reported by Coverity. Signed-off-by: Viktor Malik Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20250129071857.75182-1-vmalik@redhat.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- tools/bpf/bpftool/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index eefa2b34e641a..33065b17900fa 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -311,10 +311,11 @@ int get_fd_type(int fd) p_err("can't read link type: %s", strerror(errno)); return -1; } - if (n == sizeof(path)) { + if (n == sizeof(buf)) { p_err("can't read link type: path too long!"); return -1; } + buf[n] = '\0'; if (strstr(buf, "bpf-map")) return BPF_OBJ_MAP; -- 2.39.5