Messages in this thread | | | Date | Thu, 1 Jun 2023 17:48:17 +0100 | From | Lee Jones <> | Subject | Re: [PATCH 1/1] net/sched: cls_u32: Fix reference counter leak leading to overflow |
| |
On Thu, 01 Jun 2023, Eric Dumazet wrote:
> On Thu, Jun 1, 2023 at 4:06 PM Lee Jones <lee@kernel.org> wrote: > > > > On Wed, 31 May 2023, Jamal Hadi Salim wrote: > > > > > On Wed, May 31, 2023 at 11:03 AM Eric Dumazet <edumazet@google.com> wrote: > > > > > > > > On Wed, May 31, 2023 at 4:16 PM 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'. > > > > > > > > > > Cc: stable@kernel.org # v4.14+ > > > > > > > > Please add a Fixes: tag. > > > > Why? > > How have you identified v4.14+ ? > > Probably you did some research/"git archeology". > > By adding the Fixes: tag, you allow us to double check immediately, > and see if other bugs need to be fixed at the same time. > > You can also CC blamed patch authors, to get some feedback. > > Otherwise, we (people reviewing this patch) have to also do this > research from scratch. > > In this case, it seems bug was added in > > commit 705c7091262d02b09eb686c24491de61bf42fdb2 > Author: Jiri Pirko <jiri@resnulli.us> > Date: Fri Aug 4 14:29:14 2017 +0200 > > net: sched: cls_u32: no need to call tcf_exts_change for newly > allocated struct > > > A nice Fixes: tag would then be > > Fixes: 705c7091262d ("net: sched: cls_u32: no need to call > tcf_exts_change for newly allocated struct")
Thanks for digging this out. I will add it.
-- Lee Jones [李琼斯]
| |