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author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-09-15 18:40:05 +0200 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-10-31 17:01:44 +0100 |
commit | a2e9011b4164894594bf0b2a2a59e9c55c58c17b (patch) | |
tree | 944ce67af7f759c6fa731e9d15c85385ef8e2c0d | |
parent | e64e353590c2584b41cd1db925f67042a05f4250 (diff) | |
download | hqemu-a2e9011b4164894594bf0b2a2a59e9c55c58c17b.zip hqemu-a2e9011b4164894594bf0b2a2a59e9c55c58c17b.tar.gz |
ivshmem: Check ivshmem_read() size argument
The third argument to the fd_read() callback implemented by
ivshmem_read() is the number of bytes, not a flags field. Fix this and
check we received enough bytes before accessing the buffer pointer.
Cc: Cam Macdonell <cam@cs.ualberta.ca>
Reported-by: Sebastian Krahmer <krahmer@suse.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[AF: Handle partial reads via FIFO]
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-stable@nongnu.org
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | hw/misc/ivshmem.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index bd9d718..caeee1e 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -24,6 +24,7 @@ #include "migration/migration.h" #include "qapi/qmp/qerror.h" #include "qemu/event_notifier.h" +#include "qemu/fifo8.h" #include "sysemu/char.h" #include <sys/mman.h> @@ -73,6 +74,7 @@ typedef struct IVShmemState { CharDriverState **eventfd_chr; CharDriverState *server_chr; + Fifo8 incoming_fifo; MemoryRegion ivshmem_mmio; /* We might need to register the BAR before we actually have the memory. @@ -424,14 +426,35 @@ static void increase_dynamic_storage(IVShmemState *s, int new_min_size) { } } -static void ivshmem_read(void *opaque, const uint8_t * buf, int flags) +static void ivshmem_read(void *opaque, const uint8_t *buf, int size) { IVShmemState *s = opaque; int incoming_fd, tmp_fd; int guest_max_eventfd; long incoming_posn; - memcpy(&incoming_posn, buf, sizeof(long)); + if (fifo8_is_empty(&s->incoming_fifo) && size == sizeof(incoming_posn)) { + memcpy(&incoming_posn, buf, size); + } else { + const uint8_t *p; + uint32_t num; + + IVSHMEM_DPRINTF("short read of %d bytes\n", size); + num = MAX(size, sizeof(long) - fifo8_num_used(&s->incoming_fifo)); + fifo8_push_all(&s->incoming_fifo, buf, num); + if (fifo8_num_used(&s->incoming_fifo) < sizeof(incoming_posn)) { + return; + } + size -= num; + buf += num; + p = fifo8_pop_buf(&s->incoming_fifo, sizeof(incoming_posn), &num); + g_assert(num == sizeof(incoming_posn)); + memcpy(&incoming_posn, p, sizeof(incoming_posn)); + if (size > 0) { + fifo8_push_all(&s->incoming_fifo, buf, size); + } + } + /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr); IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd); @@ -663,6 +686,8 @@ static int pci_ivshmem_init(PCIDevice *dev) s->ivshmem_size = ivshmem_get_size(s); } + fifo8_create(&s->incoming_fifo, sizeof(long)); + register_savevm(DEVICE(dev), "ivshmem", 0, 0, ivshmem_save, ivshmem_load, dev); @@ -796,6 +821,7 @@ static void pci_ivshmem_uninit(PCIDevice *dev) memory_region_del_subregion(&s->bar, &s->ivshmem); vmstate_unregister_ram(&s->ivshmem, DEVICE(dev)); unregister_savevm(DEVICE(dev), "ivshmem", s); + fifo8_destroy(&s->incoming_fifo); } static Property ivshmem_properties[] = { |