From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) (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 C624A16DEB1 for ; Fri, 19 Sep 2025 03:48:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758253725; cv=none; b=V/9o3EJkIm5LYgxWcDlf5LvMcy0/2oD9sIYvg5DeDHlxvEW8U0TZJN6Y6Pdu4JATnr0ADjwYW8j0MjAeDJzei3ILDs8/vQ3yRydtV9SC5qIwGbBn9l7d2ZLEt7iqHgwy8Jkndxe+6YJoHHNlPgeb/Wv7LyJypIyIVpbIMZ234Hg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758253725; c=relaxed/simple; bh=t0TUZMoqcyyvjMgqGMC9XknLcszUmfsJMgTCFnESNn4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DzvI89HB7OM1h+Dh6RSMW2Pz94FwHh+BwmHnLKj2O5MRuKkcbURNWs9zpEkZJ2n/N0YTCYZGkoYzZDYTKUAMbNNiBUj7kdzlL5Ma358sqDWg/8aoUmgJr3OJz3xexj6avfe8g1NMQgEiaL/HNQ8mAhrMFaoSq60AZFRBv/+d0Oc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=bm9mRS1J; arc=none smtp.client-ip=95.215.58.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="bm9mRS1J" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1758253722; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sHeYRPdh/rpywj8JSWi2AobwgPPf4ZE2AxzDFpM7ZOg=; b=bm9mRS1J8M189+dpURaALd9jQX+Hm8QsZPHd/Dq3py/MDiAyL9mEIq5i8aEd8Iw61aGDFv Ckdph5ZOopbTBeNO8JRhK4+mmybKqNOFFJUYKvBzzyWPzCgXKdLGxAVrFYW6rEcHCo/s6m zjt1GZ5edY+BMgFVa3UPS/x9sceMQnE= From: Tao Chen To: qmo@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, chen.dylane@linux.dev Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next v4 2/2] bpftool: Fix UAF in get_delegate_value Date: Fri, 19 Sep 2025 11:48:16 +0800 Message-ID: <20250919034816.1287280-2-chen.dylane@linux.dev> In-Reply-To: <20250919034816.1287280-1-chen.dylane@linux.dev> References: <20250919034816.1287280-1-chen.dylane@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT The return value ret pointer is pointing opts_copy, but opts_copy gets freed in get_delegate_value before return, fix this by free the mntent->mnt_opts strdup memory after show delegate value. Fixes: 2d812311c2b2 ("bpftool: Add bpf_token show") Signed-off-by: Tao Chen --- tools/bpf/bpftool/token.c | 90 ++++++++++++++++----------------------- 1 file changed, 37 insertions(+), 53 deletions(-) diff --git a/tools/bpf/bpftool/token.c b/tools/bpf/bpftool/token.c index 82b829e44c8..2bbec4c98f2 100644 --- a/tools/bpf/bpftool/token.c +++ b/tools/bpf/bpftool/token.c @@ -20,6 +20,16 @@ #define MOUNTS_FILE "/proc/mounts" +struct { + const char *header; + const char *key; +} sets[] = { + {"allowed_cmds", "delegate_cmds"}, + {"allowed_maps", "delegate_maps"}, + {"allowed_progs", "delegate_progs"}, + {"allowed_attachs", "delegate_attachs"}, +}; + static bool has_delegate_options(const char *mnt_ops) { return strstr(mnt_ops, "delegate_cmds") || @@ -28,15 +38,14 @@ static bool has_delegate_options(const char *mnt_ops) strstr(mnt_ops, "delegate_attachs"); } -static char *get_delegate_value(const char *opts, const char *key) +static char *get_delegate_value(char *opts, const char *key) { char *token, *rest, *ret = NULL; - char *opts_copy = strdup(opts); - if (!opts_copy) + if (!opts) return NULL; - for (token = strtok_r(opts_copy, ",", &rest); token; + for (token = strtok_r(opts, ",", &rest); token; token = strtok_r(NULL, ",", &rest)) { if (strncmp(token, key, strlen(key)) == 0 && token[strlen(key)] == '=') { @@ -44,24 +53,19 @@ static char *get_delegate_value(const char *opts, const char *key) break; } } - free(opts_copy); return ret; } -static void print_items_per_line(const char *input, int items_per_line) +static void print_items_per_line(char *input, int items_per_line) { - char *str, *rest, *strs; + char *str, *rest; int cnt = 0; if (!input) return; - strs = strdup(input); - if (!strs) - return; - - for (str = strtok_r(strs, ":", &rest); str; + for (str = strtok_r(input, ":", &rest); str; str = strtok_r(NULL, ":", &rest)) { if (cnt % items_per_line == 0) printf("\n\t "); @@ -69,38 +73,31 @@ static void print_items_per_line(const char *input, int items_per_line) printf("%-20s", str); cnt++; } - - free(strs); } #define ITEMS_PER_LINE 4 static void show_token_info_plain(struct mntent *mntent) { - char *value; + size_t i; printf("token_info %s", mntent->mnt_dir); - printf("\n\tallowed_cmds:"); - value = get_delegate_value(mntent->mnt_opts, "delegate_cmds"); - print_items_per_line(value, ITEMS_PER_LINE); - - printf("\n\tallowed_maps:"); - value = get_delegate_value(mntent->mnt_opts, "delegate_maps"); - print_items_per_line(value, ITEMS_PER_LINE); + for (i = 0; i < ARRAY_SIZE(sets); i++) { + char *opts, *value; - printf("\n\tallowed_progs:"); - value = get_delegate_value(mntent->mnt_opts, "delegate_progs"); - print_items_per_line(value, ITEMS_PER_LINE); + printf("\n\t%s:", sets[i].header); + opts = strdup(mntent->mnt_opts); + value = get_delegate_value(opts, sets[i].key); + print_items_per_line(value, ITEMS_PER_LINE); + free(opts); + } - printf("\n\tallowed_attachs:"); - value = get_delegate_value(mntent->mnt_opts, "delegate_attachs"); - print_items_per_line(value, ITEMS_PER_LINE); printf("\n"); } -static void split_json_array_str(const char *input) +static void split_json_array_str(char *input) { - char *str, *rest, *strs; + char *str, *rest; if (!input) { jsonw_start_array(json_wtr); @@ -108,43 +105,30 @@ static void split_json_array_str(const char *input) return; } - strs = strdup(input); - if (!strs) - return; - jsonw_start_array(json_wtr); - for (str = strtok_r(strs, ":", &rest); str; + for (str = strtok_r(input, ":", &rest); str; str = strtok_r(NULL, ":", &rest)) { jsonw_string(json_wtr, str); } jsonw_end_array(json_wtr); - - free(strs); } static void show_token_info_json(struct mntent *mntent) { - char *value; + size_t i; jsonw_start_object(json_wtr); - jsonw_string_field(json_wtr, "token_info", mntent->mnt_dir); - jsonw_name(json_wtr, "allowed_cmds"); - value = get_delegate_value(mntent->mnt_opts, "delegate_cmds"); - split_json_array_str(value); + for (i = 0; i < ARRAY_SIZE(sets); i++) { + char *opts, *value; - jsonw_name(json_wtr, "allowed_maps"); - value = get_delegate_value(mntent->mnt_opts, "delegate_maps"); - split_json_array_str(value); - - jsonw_name(json_wtr, "allowed_progs"); - value = get_delegate_value(mntent->mnt_opts, "delegate_progs"); - split_json_array_str(value); - - jsonw_name(json_wtr, "allowed_attachs"); - value = get_delegate_value(mntent->mnt_opts, "delegate_attachs"); - split_json_array_str(value); + jsonw_name(json_wtr, sets[i].header); + opts = strdup(mntent->mnt_opts); + value = get_delegate_value(opts, sets[i].key); + split_json_array_str(value); + free(opts); + } jsonw_end_object(json_wtr); } -- 2.48.1