Messages in this thread | | | From | Eric Dumazet <> | Date | Thu, 8 Jun 2023 09:31:07 +0200 | 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 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 !
Reviewed-by: Eric Dumazet <edumazet@google.com>
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