Re: [PATCH] mm: Fix int overflow in callers of do_shrink_slab()

[Josef Bacik]

On Fri, Sep 28, 2018 at 02:28:32PM +0300, Kirill Tkhai wrote:
> do_shrink_slab() returns unsigned long value, and
> the placing into int variable cuts high bytes off.
> Then we compare ret and 0xfffffffe (since SHRINK_EMPTY
> is converted to ret type).
> 
> Thus, big number of objects returned by do_shrink_slab()
> may be interpreted as SHRINK_EMPTY, if low bytes of
> their value are equal to 0xfffffffe. Fix that
> by declaration ret as unsigned long in these functions.
> 
> Reported-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
> Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>

Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>

Thanks,

Josef