From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Price Date: Mon, 19 Aug 2013 16:18:11 +0100 Subject: [Cluster-devel] [PATCH] fsck.gfs2: Allocate enough space for the block map Message-ID: <1376925491-26225-1-git-send-email-anprice@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Building with gcc 4.8's address sanitizer and running the test suite throws up an issue where the block map allocated in fsck.gfs2 is not large enough when the required size is an odd number. For example, when the number of blocks is 3, the mapsize (number of chars to allocate memory for) would be (3 >> 1) which is too small as each block requires 4 bits. This patch adds 1 to the mapsize, as suggested in an existing comment, to ensure we have enough space in these situations. Note that this has (probably) never made fsck.gfs2 misbehave as it only ever accessed 4 bits past the end of the block map and by chance that memory was never being modified by anything else in the rare cases in which it was used. Resolves: bz#947384 Signed-off-by: Andrew Price --- gfs2/fsck/util.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/gfs2/fsck/util.c b/gfs2/fsck/util.c index 408d89a..3e3050f 100644 --- a/gfs2/fsck/util.c +++ b/gfs2/fsck/util.c @@ -534,15 +534,10 @@ static int gfs2_blockmap_create(struct gfs2_bmap *bmap, uint64_t size) /* Have to add 1 to BLOCKMAP_SIZE since it's 0-based and mallocs * must be 1-based */ - bmap->mapsize = BLOCKMAP_SIZE4(size); + bmap->mapsize = BLOCKMAP_SIZE4(size) + 1; - if (!(bmap->map = malloc(sizeof(char) * bmap->mapsize))) + if (!(bmap->map = calloc(bmap->mapsize, sizeof(char)))) return -ENOMEM; - if (!memset(bmap->map, 0, sizeof(char) * bmap->mapsize)) { - free(bmap->map); - bmap->map = NULL; - return -ENOMEM; - } return 0; } -- 1.8.3.1