Messages in this thread | | | From | Jamal Hadi Salim <> | Date | Thu, 8 Jun 2023 12:40:09 -0400 | Subject | Re: [PATCH v2 1/1] net/sched: cls_u32: Fix reference counter leak leading to overflow |
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On Thu, Jun 8, 2023 at 3:47 AM Lee Jones <lee@kernel.org> wrote: > > On Thu, 08 Jun 2023, Eric Dumazet wrote: > > > On Thu, Jun 8, 2023 at 9:29 AM Lee Jones <lee@kernel.org> wrote: > > > > > > In the event of a failure in tcf_change_indev(), u32_set_parms() will > > > immediately return without decrementing the recently incremented > > > reference counter. If this happens enough times, the counter will > > > rollover and the reference freed, leading to a double free which can be > > > used to do 'bad things'. > > > > > > In order to prevent this, move the point of possible failure above the > > > point where the reference counter is incremented. Also save any > > > meaningful return values to be applied to the return data at the > > > appropriate point in time. > > > > > > This issue was caught with KASAN. > > > > > > Fixes: 705c7091262d ("net: sched: cls_u32: no need to call tcf_exts_change for newly allocated struct") > > > Suggested-by: Eric Dumazet <edumazet@google.com> > > > Signed-off-by: Lee Jones <lee@kernel.org> > > > --- > > > > Thanks Lee ! > > No problem. Thanks for your help. > > > Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
cheers, jamal
> -- > Lee Jones [李琼斯]
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