mm/slab_common: Replace invocation of weak PRNG

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The Slab allocator randomization inside slab_common.c
uses the prandom_u32 PRNG. That was added to prevent attackers to obtain
information on the heap state.

However, this PRNG turned out to be weak, as noted in commit c51f8f88d7
To fix it, we have changed the invocation of prandom_u32_state to get_random_u32
to ensure the PRNG is strong.

Since a modulo operation is applied right after that,
in the Fisher-Yates shuffle, we used get_random_u32_below, to achieve uniformity.

Signed-off-by: David Keisar Schmidt <david.keisarschm@mail.huji.ac.il>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

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David Keisar Schmidt 2023-04-16 20:22:55 +03:00 • committed by Vlastimil Babka

parent f7e466e951

commit ffe4dfe0ba

1 changed files with 3 additions and 8 deletions

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mm/slab_common.c

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