Re: [Qemu-devel] [PATCH v2 00/20] block: Handle failure for potentially large allocations

[Markus Armbruster]

Kevin Wolf <address@hidden> writes:

> A not too small part of the recent CVEs were DoS scenarios by letting
> qemu abort with too large memory allocations. We generally "fixed" these
> cases by setting some limits on values read from image files that
> influence the size of allocations.

Just double-checking: do these limits ensure the size calculations in
arguments of g_malloc() etc. can't overflow?

> Because we still need to allow reading large images, this works only to
> a certain degree and we still can get fairly large allocations, which
> are not unthinkable to fail on some machines.
>
> This series converts potentially large allocations to g_try_malloc() and
> friends and handles failure gracefully e.g. by returning -ENOMEM. This
> may cause hot-plug of a new disk or individual requests to fail, but the
> VM as a whole can keep running.

I guess the resulting error paths are untested.  Just sayin', I'm not
asking you to test them.

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