From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755067AbdKASqq (ORCPT ); Wed, 1 Nov 2017 14:46:46 -0400 Received: from a2nlsmtp01-04.prod.iad2.secureserver.net ([198.71.225.38]:52276 "EHLO a2nlsmtp01-04.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754978AbdKASqm (ORCPT ); Wed, 1 Nov 2017 14:46:42 -0400 x-originating-ip: 107.180.71.197 From: Long Li To: "K . Y . Srinivasan" , Haiyang Zhang , Stephen Hemminger , devel@linuxdriverproject.org, linux-kernel@vger.kernel.org Cc: Paul Meyer , Long Li Subject: [Revised PATCH v2] hv: kvp: Avoid reading past allocated blocks from KVP file Date: Wed, 1 Nov 2017 11:45:26 -0700 Message-Id: <20171101184526.1689-1-longli@exchange.microsoft.com> X-Mailer: git-send-email 2.14.1 X-CMAE-Envelope: MS4wfMFxHAX6J43b/vV8kJF99cqQAtkE1RyWeS1JfXVnq/aLgABduYrbqZkkq3Pq5BxBRXOfpta/TxZ7TZUWQrun8EZDZeUEeevsM2fQoKZYEfZt0N1U+/Ql LxGAS/0P4tpleYxYSkfw6F6N1faqRj2n+nTjHSsUgnF+XpXsvsLDIjfzWJaw7ZU+jWe31/ICtAGMLEGUrys/GCAWh27WB6U8tHaaGY0vZ+GJYdlX8eMo7VaB sUqW1DeoiFlVv4Q11D/vC4a8fZEFtdey4jPaFbcUVF85EebmpyHHpzINiKg55yYLq2CtBU8GWFqPV4Ts2J/ZlS+UjQmkT2yddsU1Ehlge9ji2g5aJClI00hs W7W1Cqu8HH0iKhTL5OQ2bLnOrZtITHEUoKoDKgWbO5mR8cyc33o= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Meyer While reading in more than one block (50) of KVP records, the allocation goes per block, but the reads used the total number of allocated records (without resetting the pointer/stream). This causes the records buffer to overrun when the refresh reads more than one block over the previous capacity (e.g. reading more than 100 KVP records whereas the in-memory database was empty before). Fix this by reading the correct number of KVP records from file each time. Changes since v1: 1. Properly wrapped comment texts. 2. Added the 2nd Signed-off-by. Signed-off-by: Paul Meyer Signed-off-by: Long Li --- tools/hv/hv_kvp_daemon.c | 66 ++++++++---------------------------------------- 1 file changed, 10 insertions(+), 56 deletions(-) diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index eaa3bec..2094036 100644 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -193,11 +193,13 @@ static void kvp_update_mem_state(int pool) for (;;) { readp = &record[records_read]; records_read += fread(readp, sizeof(struct kvp_record), - ENTRIES_PER_BLOCK * num_blocks, - filep); + ENTRIES_PER_BLOCK * num_blocks - records_read, + filep); if (ferror(filep)) { - syslog(LOG_ERR, "Failed to read file, pool: %d", pool); + syslog(LOG_ERR, + "Failed to read file, pool: %d; error: %d %s", + pool, errno, strerror(errno)); exit(EXIT_FAILURE); } @@ -224,15 +226,11 @@ static void kvp_update_mem_state(int pool) fclose(filep); kvp_release_lock(pool); } + static int kvp_file_init(void) { int fd; - FILE *filep; - size_t records_read; char *fname; - struct kvp_record *record; - struct kvp_record *readp; - int num_blocks; int i; int alloc_unit = sizeof(struct kvp_record) * ENTRIES_PER_BLOCK; @@ -246,61 +244,17 @@ static int kvp_file_init(void) for (i = 0; i < KVP_POOL_COUNT; i++) { fname = kvp_file_info[i].fname; - records_read = 0; - num_blocks = 1; sprintf(fname, "%s/.kvp_pool_%d", KVP_CONFIG_LOC, i); fd = open(fname, O_RDWR | O_CREAT | O_CLOEXEC, 0644 /* rw-r--r-- */); if (fd == -1) return 1; - - filep = fopen(fname, "re"); - if (!filep) { - close(fd); - return 1; - } - - record = malloc(alloc_unit * num_blocks); - if (record == NULL) { - fclose(filep); - close(fd); - return 1; - } - for (;;) { - readp = &record[records_read]; - records_read += fread(readp, sizeof(struct kvp_record), - ENTRIES_PER_BLOCK, - filep); - - if (ferror(filep)) { - syslog(LOG_ERR, "Failed to read file, pool: %d", - i); - exit(EXIT_FAILURE); - } - - if (!feof(filep)) { - /* - * We have more data to read. - */ - num_blocks++; - record = realloc(record, alloc_unit * - num_blocks); - if (record == NULL) { - fclose(filep); - close(fd); - return 1; - } - continue; - } - break; - } kvp_file_info[i].fd = fd; - kvp_file_info[i].num_blocks = num_blocks; - kvp_file_info[i].records = record; - kvp_file_info[i].num_records = records_read; - fclose(filep); - + kvp_file_info[i].num_blocks = 1; + kvp_file_info[i].records = malloc(alloc_unit); + kvp_file_info[i].num_records = 0; + kvp_update_mem_state(i); } return 0; -- 2.7.4