From: Philippe Mathieu-Daudé Date: Fri, 3 Sep 2021 09:59:27 +0000 (+0200) Subject: block/qcow2-bitmap: Replace g_memdup() by g_memdup2() X-Git-Tag: v9.1.0-rc0~114^2~27 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f9cc8cfdf346cadc92db8fce32c8b5d7f1095163;p=thirdparty%2Fqemu.git block/qcow2-bitmap: Replace g_memdup() by g_memdup2() 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 --- diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 874ea569485..256ec998788 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);