From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60411) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9Gzx-00046d-1w for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:36:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y9Gzi-0006hb-Tj for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:35:52 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:56728) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9Gzh-0006gt-W1 for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:35:38 -0500 Received: from /spool/local by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 8 Jan 2015 10:35:37 -0700 From: Michael Roth Date: Thu, 8 Jan 2015 11:33:51 -0600 Message-Id: <1420738472-23267-48-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1420738472-23267-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1420738472-23267-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 47/88] qcow2: Do not overflow when writing an L1 sector List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org From: Max Reitz While writing an L1 table sector, qcow2_write_l1_entry() copies the respective range from s->l1_table to the local "buf" array. The size of s->l1_table does not have to be a multiple of L1_ENTRIES_PER_SECTOR; thus, limit the index which is used for copying all entries to the L1 size. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz Reviewed-by: Peter Lieven Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf (cherry picked from commit a1391444fe1cfef14976458f3293a2c6945e725c) Signed-off-by: Michael Roth --- block/qcow2-cluster.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 4208dc0..26827a2 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -158,12 +158,14 @@ static int l2_load(BlockDriverState *bs, uint64_t l2_offset, int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index) { BDRVQcowState *s = bs->opaque; - uint64_t buf[L1_ENTRIES_PER_SECTOR]; + uint64_t buf[L1_ENTRIES_PER_SECTOR] = { 0 }; int l1_start_index; int i, ret; l1_start_index = l1_index & ~(L1_ENTRIES_PER_SECTOR - 1); - for (i = 0; i < L1_ENTRIES_PER_SECTOR; i++) { + for (i = 0; i < L1_ENTRIES_PER_SECTOR && l1_start_index + i < s->l1_size; + i++) + { buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]); } -- 1.9.1