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 6CACE3A91D5; Mon, 5 May 2025 23:18:05 +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=1746487086; cv=none; b=Ewuh9hglnBtDCkr9Y1Y95CV7EgcaATPgWLPTsQOhuMdoTuVmcBemWia9XASCCyAZQq87wElOlytmWbydoFsLx/yB6f6kKQTHdDauds2iOAXq9Bmyz0FTnDRNlQDTBRMP3JKRE173Q4E5t6ktJTsERnRg4VfzRNth4X+Am/qiA4w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487086; c=relaxed/simple; bh=sCRF0bOX0We3UPuKxBWiR1cOc+j4HkGJU7wJ+k2QiZU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=g8BUZ35bYwbSlO+GIak2Wjgvmb7yDa2nYJ6tWYf8dSQGtffrOSZuLLa0WguAv7gCGe8G9VF9p1t2OmCLuYLhrdWqp6JVPYzy4Ucr0qV6KaBkcEtrLrRmaixcJLPJwMUft4lfomRhLICP7Q+y+JK+IhEncEELWr7UuogTfglCjNE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uvdyx/lY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uvdyx/lY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 54627C4CEEF; Mon, 5 May 2025 23:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487085; bh=sCRF0bOX0We3UPuKxBWiR1cOc+j4HkGJU7wJ+k2QiZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uvdyx/lYR2+554zg6e9D3o4UkPGPRVZQjcZj81o4Aoda1Hrhh/F0eaHSw9En1dv/r IbqPiwGYb4Q+LkmBiCYdex0DW2O3mRV/i0L+afuk1ZNj5cwQVJAKDfJH5yJBKUom3y CEH6p/ByrlAum5PhvZcG+AbthtwaR8xyIVtV+w/BJWdbIT3aVYLgtx/7HeHS3Dgrog 5U3S7+NFskXsOCAO65z4q1CpYlEPxi6hAa0PBl1jwb4lw0Gssdw/gL4otZGM65hNgV ZmsmTplp3Y/lu+deJPybF5n6cENA+eM7+QbVmaKOfw6TzLs0ke9ZU/+xFaC6a6R41s fDgJUFQXTs6PA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Viktor Malik , Andrii Nakryiko , Quentin Monnet , Alexei Starovoitov , Sasha Levin , daniel@iogearbox.net, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 146/153] bpftool: Fix readlink usage in get_fd_type Date: Mon, 5 May 2025 19:13:13 -0400 Message-Id: <20250505231320.2695319-146-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231320.2695319-1-sashal@kernel.org> References: <20250505231320.2695319-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.181 Content-Transfer-Encoding: 8bit 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 e4c65d34fe74f..2b4773e00ab68 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -318,10 +318,11 @@ 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