exec: use qemu_ram_ptr_length to access guest ram

When accessing guest's ram block during DMA operation, use
'qemu_ram_ptr_length' to get ram block pointer. It ensures
that DMA operation of given length is possible; And avoids
any OOB memory access situations.

Reported-by: Alex <broscutamaker@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20170712123840.29328-1-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Prasad J Pandit 2017-07-12 18:08:40 +05:30 committed by Paolo Bonzini
parent 1a29cc8f5e
commit 04bf2526ce

4
exec.c
View File

@ -2929,7 +2929,7 @@ static MemTxResult address_space_write_continue(AddressSpace *as, hwaddr addr,
}
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l);
memcpy(ptr, buf, l);
invalidate_and_set_dirty(mr, addr1, l);
}
@ -3020,7 +3020,7 @@ MemTxResult address_space_read_continue(AddressSpace *as, hwaddr addr,
}
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l);
memcpy(buf, ptr, l);
}