Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756841Ab0LMXq2 (ORCPT ); Mon, 13 Dec 2010 18:46:28 -0500 Received: from swampdragon.chaosbits.net ([90.184.90.115]:23163 "EHLO swampdragon.chaosbits.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755602Ab0LMXq1 (ORCPT ); Mon, 13 Dec 2010 18:46:27 -0500 Date: Tue, 14 Dec 2010 00:40:04 +0100 (CET) From: Jesper Juhl To: linux-kernel@vger.kernel.org cc: linux-raid@vger.kernel.org, dm-devel@redhat.com, Neil Brown Subject: [PATCH][rfc] md: Close mem leak in userspace_ctr() Message-ID: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2609 Lines: 85 Hi, There's a small memory leak in drivers/md/dm-log-userspace-base.c::userspace_ctr(). The call to build_constructor_string() dynamically allocates memory for its last argument, but we do not always clean up that allocated memory. The patch below closes the leak and also removes some unneeded local variables and some pointless assignments. If the patch looks good, please consider applying it - if not, please tell me where I messed up. Signed-off-by: Jesper Juhl --- dm-log-userspace-base.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) Compile tested only. diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c index 1ed0094..71a3049 100644 --- a/drivers/md/dm-log-userspace-base.c +++ b/drivers/md/dm-log-userspace-base.c @@ -99,26 +99,22 @@ static int build_constructor_string(struct dm_target *ti, char **ctr_str) { int i, str_size; - char *str = NULL; - - *ctr_str = NULL; for (i = 0, str_size = 0; i < argc; i++) str_size += strlen(argv[i]) + 1; /* +1 for space between args */ str_size += 20; /* Max number of chars in a printed u64 number */ - str = kzalloc(str_size, GFP_KERNEL); - if (!str) { + *ctr_str = kzalloc(str_size, GFP_KERNEL); + if (!*ctr_str) { DMWARN("Unable to allocate memory for constructor string"); return -ENOMEM; } - str_size = sprintf(str, "%llu", (unsigned long long)ti->len); + str_size = sprintf(*ctr_str, "%llu", (unsigned long long)ti->len); for (i = 0; i < argc; i++) - str_size += sprintf(str + str_size, " %s", argv[i]); + str_size += sprintf(*ctr_str + str_size, " %s", argv[i]); - *ctr_str = str; return str_size; } @@ -140,7 +136,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, { int r = 0; int str_size; - char *ctr_str = NULL; + char *ctr_str; struct log_c *lc = NULL; uint64_t rdata; size_t rdata_size = sizeof(rdata); @@ -173,6 +169,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti, str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str); if (str_size < 0) { + kfree(ctr_str); kfree(lc); return str_size; } -- Jesper Juhl http://www.chaosbits.net/ Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/