Messages in this thread | | | Date | Mon, 27 Feb 2023 11:16:26 -0500 | From | Steven Rostedt <> | Subject | Re: BUG: unable to handle kernel NULL pointer dereference in rcu_core |
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On Tue, 28 Feb 2023 00:11:51 +0800 Zhouyi Zhou <zhouzhouyi@gmail.com> wrote:
> > Yes certainly, the rcu_head is allocated on the caller side so it > > could have been trampled while the callback was still in flight. > Thank you all for your guidance, I learned a lot during this process > > > > > OR it could be a bug with RCU if the synchronize_rcu() ended before the > > > grace periods have finished. > Thanks again. > > By the way, the syzkaller on my local machine has been running for 8 > hours, only three bugs reported[1][2][3], but they don't seem to be > related to Sanan's original report. > Maybe there are some configuration mismatches between us.The test > continues, I will report to you once I have any new discovery.
Note, the above races (either bug, the one that tramples on something in RCU flight, or a synchronize_sched() returning early) may be extremely hard to hit. It could have been the planets were lined up just right to hit the bug, and won't happen for another 27,000 years.
-- Steve
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