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. g_memdup() as been deprecated in GLib 2.68. Since QEMU defines GLIB_VERSION_MAX_ALLOWED to GLIB_VERSION_2_56, the deprecation is not displayed (on GLib >= 2.68 such available on Fedora 34). However the function is still unsafe, so it is better to avoid its use. This series provides the safely equivalent g_memdup2() wrapper, and replace all g_memdup() calls by it. The previous link recommend to audit the call sites. Most of the calls use byte_size=sizeof(STRUCT), and no STRUCT appears to be > 4GiB. Few calls use unsigned/size_t/uint16_t. Where code is doing multiplication, patches are sent as RFC. In particular: hw/net/virtio-net.c hw/virtio/virtio-crypto.c Since v1: - Added missing g_memdup2 -> g_memdup2_qemu compat definition (danpb) - Do not call g_memdup2_qemu() but directly g_memdup2() (danpb) Tested with the following snippet: -- >8 -- diff --git a/include/glib-compat.h b/include/glib-compat.h index 8d01a8c01fb..2b33dea71a8 100644 --- a/include/glib-compat.h +++ b/include/glib-compat.h @@ -21,3 +21,3 @@ */ -#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_56 +#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_68 @@ -26,3 +26,3 @@ */ -#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_56 +#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_68 --- Philippe Mathieu-Daudé (28): hw/hyperv/vmbus: Remove unused vmbus_load/save_req() glib-compat: Introduce g_memdup2() wrapper qapi: Replace g_memdup() by g_memdup2() accel/tcg: Replace g_memdup() by g_memdup2() block/qcow2-bitmap: Replace g_memdup() by g_memdup2() softmmu: Replace g_memdup() by g_memdup2() hw/9pfs: Replace g_memdup() by g_memdup2() hw/acpi: Avoid truncating acpi_data_len() to 32-bit hw/acpi: Replace g_memdup() by g_memdup2() hw/core/machine: Replace g_memdup() by g_memdup2() hw/hppa/machine: Replace g_memdup() by g_memdup2() hw/i386/multiboot: Replace g_memdup() by g_memdup2() hw/net/eepro100: Replace g_memdup() by g_memdup2() hw/nvram/fw_cfg: Replace g_memdup() by g_memdup2() hw/scsi/mptsas: Replace g_memdup() by g_memdup2() hw/ppc/spapr_pci: Replace g_memdup() by g_memdup2() hw/rdma: Replace g_memdup() by g_memdup2() hw/vfio/pci: Replace g_memdup() by g_memdup2() hw/virtio: Replace g_memdup() by g_memdup2() net/colo: Replace g_memdup() by g_memdup2() ui/clipboard: Replace g_memdup() by g_memdup2() linux-user: Replace g_memdup() by g_memdup2() tests/unit: Replace g_memdup() by g_memdup2() tests/qtest: Replace g_memdup() by g_memdup2() target/arm: Replace g_memdup() by g_memdup2() target/ppc: Replace g_memdup() by g_memdup2() contrib: Replace g_memdup() by g_memdup2() checkpatch: Do not allow deprecated g_memdup() include/glib-compat.h | 37 +++++++++++++++++++++++ include/hw/hyperv/vmbus.h | 3 -- accel/tcg/cputlb.c | 8 ++--- block/qcow2-bitmap.c | 2 +- contrib/plugins/lockstep.c | 2 +- contrib/rdmacm-mux/main.c | 10 +++---- hw/9pfs/9p-synth.c | 2 +- hw/9pfs/9p.c | 2 +- hw/acpi/core.c | 3 +- hw/arm/virt-acpi-build.c | 2 +- hw/core/machine.c | 4 +-- hw/hppa/machine.c | 8 ++--- hw/hyperv/vmbus.c | 59 ------------------------------------- hw/i386/acpi-build.c | 6 ++-- hw/i386/multiboot.c | 2 +- hw/net/eepro100.c | 2 +- hw/net/virtio-net.c | 3 +- hw/nvram/fw_cfg.c | 9 +++--- hw/ppc/spapr_pci.c | 7 ++--- hw/rdma/rdma_utils.c | 2 +- hw/scsi/mptsas.c | 5 ++-- hw/vfio/pci.c | 2 +- hw/virtio/virtio-crypto.c | 6 ++-- linux-user/syscall.c | 2 +- linux-user/uaccess.c | 2 +- net/colo.c | 4 +-- qapi/qapi-clone-visitor.c | 16 +++++----- qapi/qapi-visit-core.c | 6 ++-- softmmu/memory.c | 2 +- softmmu/vl.c | 2 +- target/arm/helper.c | 6 ++-- target/ppc/mmu-hash64.c | 2 +- tests/qtest/libqos/ahci.c | 6 ++-- tests/qtest/libqos/qgraph.c | 2 +- tests/unit/ptimer-test.c | 22 +++++++------- tests/unit/test-iov.c | 26 ++++++++-------- ui/clipboard.c | 2 +- scripts/checkpatch.pl | 5 ++++ 38 files changed, 138 insertions(+), 153 deletions(-) -- 2.31.1