| From | Tavis Ormandy <> | Subject | Re: [PATCH 186/190] Revert "virt: vbox: Only copy_from_user the request-header once" | Date | Wed, 21 Apr 2021 15:14:29 -0000 (UTC) |
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On 2021-04-21, Greg Kroah-Hartman wrote: > This reverts commit bd23a7269834dc7c1f93e83535d16ebc44b75eba. > > - *((struct vbg_ioctl_hdr *)buf) = hdr; > - if (copy_from_user(buf + sizeof(hdr), (void *)arg + sizeof(hdr), > - hdr.size_in - sizeof(hdr))) { > + if (copy_from_user(buf, (void *)arg, hdr.size_in)) { > ret = -EFAULT; > goto out; > }
This one seems like a real bugfix, otherwise there's a double-fetch from userspace, and a TOCTOU with the hdr fields that could cause a OOB read.
Reviewed-by: Tavis Ormandy <taviso@gmail.com>
Tavis.
-- _o) $ lynx lock.cmpxchg8b.com /\\ _o) _o) $ finger taviso@sdf.org _\_V _( ) _( ) @taviso
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