Re: [PATCH] futex: Initialize futex_phash_new during fork().

[André Almeida]

Em 23/06/2025 05:34, Sebastian Andrzej Siewior escreveu:
> During a hash resize operation the new private hash is stored in
> mm_struct::futex_phash_new if the current hash can not be immediately
> replaced.
>
> The new hash must not be copied during fork() into the new task. Doing
> so will lead to a double-free of the memory by the two tasks.
>
> Initialize the mm_struct::futex_phash_new during fork().
>
> Reported-by: Calvin Owens <calvin@xxxxxxxxxx>
> Closes: https://lore.kernel.org/all/aFBQ8CBKmRzEqIfS@xxxxxxxxxxxxx/
> Tested-by: Calvin Owens <calvin@xxxxxxxxxx>
> Fixes: bd54df5ea7cad ("futex: Allow to resize the private local hash")
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>

Reviewed-by: André Almeida <andrealmeid@xxxxxxxxxx>