From f9cc8cfdf346cadc92db8fce32c8b5d7f1095163 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Fri, 3 Sep 2021 11:59:27 +0200 Subject: [PATCH] block/qcow2-bitmap: Replace g_memdup() by g_memdup2() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Per https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538 The old API took the size of the memory to duplicate as a guint, whereas most memory functions take memory sizes as a gsize. This made it easy to accidentally pass a gsize to g_memdup(). For large values, that would lead to a silent truncation of the size from 64 to 32 bits, and result in a heap area being returned which is significantly smaller than what the caller expects. This can likely be exploited in various modules to cause a heap buffer overflow. Replace g_memdup() by the safer g_memdup2() wrapper. Trivially safe because the argument was directly from sizeof. Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Eric Blake Message-Id: <20210903174510.751630-6-philmd@redhat.com> Signed-off-by: Philippe Mathieu-Daudé --- block/qcow2-bitmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 874ea56948..256ec99878 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1609,7 +1609,7 @@ bool qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, name); goto fail; } - tb = g_memdup(&bm->table, sizeof(bm->table)); + tb = g_memdup2(&bm->table, sizeof(bm->table)); bm->table.offset = 0; bm->table.size = 0; QSIMPLEQ_INSERT_TAIL(&drop_tables, tb, entry);