Re: [PATCH -net] net: sched: prevent invalid Scell_log shift count

[David Miller]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Date: Thu, 24 Dec 2020 22:23:44 -0800

> Check Scell_log shift size in red_check_params() and modify all callers
> of red_check_params() to pass Scell_log.
> 
> This prevents a shift out-of-bounds as detected by UBSAN:
>   UBSAN: shift-out-of-bounds in ./include/net/red.h:252:22
>   shift exponent 72 is too large for 32-bit type 'int'
> 
> Fixes: 8afa10cbe281 ("net_sched: red: Avoid illegal values")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Reported-by: syzbot+97c5bd9cc81eca63d36e@xxxxxxxxxxxxxxxxxxxxxxxxx

Applied and queued up for -stable, thanks.