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 0942E22D78F; Mon, 2 Jun 2025 14:34:25 +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=1748874865; cv=none; b=YzbPOwtgRGCFvoQq33SMtUmpHbY/dhOsg3oPbfg/ueuLELu1Che0bmgGhrapuENRp7SbOGH+t4m7SO4h0Qmwm1tJZmb7um+FBnO94F6GMSIZj94oUljCL+gl7pOuHoQJemGjiDoIN6bTAOk0G3XUx2sWr5iPeKSzldfUaNESPvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748874865; c=relaxed/simple; bh=Mq8AkIxvRqRFzmIEdRH8w5iJs288RmJBbcMzFBm9tes=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kztIQjUwRvleWXPBzuRKpP1Y4pzgWzun+5ZROeUWNe5y+0XiQ+VoKnoOflJhIwHjH072tfpNOZCIyBWRtz8lmlNSgZ2wrM5/tK0LupQIHRMIy4volUq94fEWFvTYnX3OftDI2cEqlnMqJw0NT085Ipsse2RcFRULivspOyKylCU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tUdj85Dd; 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="tUdj85Dd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 41521C4CEEB; Mon, 2 Jun 2025 14:34:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748874864; bh=Mq8AkIxvRqRFzmIEdRH8w5iJs288RmJBbcMzFBm9tes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tUdj85DdmuXPoWfGIpACUu4NHfHoJioUE3KLJcXUy3q1q9dbB4L8l0AsI6fTWn9Mn gWix+LFKCw95qojMW62hAWdkSGBPWH1GluFiSbzG7lrXj4LeSSI4TEBa0ysZTRSglT RYGaukloNu3+WZ2+6gC2MjhpQ+IcGgJFjWsVgUDo= 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 5.4 160/204] bpftool: Fix readlink usage in get_fd_type Date: Mon, 2 Jun 2025 15:48:13 +0200 Message-ID: <20250602134301.944137529@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134255.449974357@linuxfoundation.org> References: <20250602134255.449974357@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 5.4-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 a209f53901b8c..91bf7575493b5 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -283,10 +283,11 @@ 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