Messages in this thread | | | Date | Mon, 27 Nov 2023 19:33:40 -0600 | Subject | Re: [PATCH] neighbour: Fix __randomize_layout crash in struct neighbour | From | "Gustavo A. R. Silva" <> |
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On 11/27/23 18:29, Kees Cook wrote: > On Sat, Nov 25, 2023 at 03:33:58PM -0600, Gustavo A. R. Silva wrote: >> Previously, one-element and zero-length arrays were treated as true >> flexible arrays, even though they are actually "fake" flex arrays. >> The __randomize_layout would leave them untouched at the end of the >> struct, similarly to proper C99 flex-array members. >> >> However, this approach changed with commit 1ee60356c2dc ("gcc-plugins: >> randstruct: Only warn about true flexible arrays"). Now, only C99 >> flexible-array members will remain untouched at the end of the struct, >> while one-element and zero-length arrays will be subject to randomization. >> >> Fix a `__randomize_layout` crash in `struct neighbour` by transforming >> zero-length array `primary_key` into a proper C99 flexible-array member. >> >> Fixes: 1ee60356c2dc ("gcc-plugins: randstruct: Only warn about true flexible arrays") >> Closes: https://lore.kernel.org/linux-hardening/20231124102458.GB1503258@e124191.cambridge.arm.com/ >> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> > > Yes, please. Do we have any other 0-sized arrays hiding out in the > kernel? We need to get these all cleared...
I've found 27 instances of zero-length fake-flex arrays in next-20231127.
I'll send a patch series to transform all of them.
> > Reviewed-by: Kees Cook <keescook@chromium.org> >
Thanks! -- Gustavo
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