| Message ID | 20210903174008.749126-1-philmd@redhat.com |
|---|---|
| Headers | show |
| Series | glib: Replace g_memdup() by g_memdup2() | expand |
On 9/3/21 7:39 PM, Philippe Mathieu-Daudé wrote: > 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) > > Philippe Mathieu-Daudé (30): > 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() > RFC hw/virtio: Replace g_memdup() by g_memdup2() > net/colo: Replace g_memdup() by g_memdup2() > RFC ui/clipboard: Replace g_memdup() by g_memdup2() > RFC 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() > f > test I figured too late I was not placed in the correct commit, please disregard this incomplete series...
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) Philippe Mathieu-Daudé (30): 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() RFC hw/virtio: Replace g_memdup() by g_memdup2() net/colo: Replace g_memdup() by g_memdup2() RFC ui/clipboard: Replace g_memdup() by g_memdup2() RFC 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() f test include/glib-compat.h | 41 ++++++++++++++++++++++++-- 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, 140 insertions(+), 155 deletions(-)