Commit 0dbaaa79 authored by Peter Maydell's avatar Peter Maydell Committed by Kevin Wolf
Browse files

block/vpc: Don't take address of fields in packed structs 



Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by generating the
UUID into a local variable which is definitely safely aligned and
then copying it into place.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 4a960ece

block/vpc.c

+3 −1
Original line number Diff line number Diff line
@@ -979,6 +979,7 @@ static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts, 
    int64_t total_size;

    int disk_type;

    int ret = -EIO;

    QemuUUID uuid;



    assert(opts->driver == BLOCKDEV_DRIVER_VPC);

    vpc_opts = &opts->u.vpc;
@@ -1062,7 +1063,8 @@ static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts, 


    footer->type = cpu_to_be32(disk_type);



    qemu_uuid_generate(&footer->uuid);

    qemu_uuid_generate(&uuid);

    footer->uuid = uuid;



    footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE));