Messages in this thread | | | Date | Fri, 25 Jun 2010 15:07:13 -0700 | From | Sukadev Bhattiprolu <> | Subject | Re: [RESEND PATCH] pid_ns: Fix proc_flush_task() accessing freed proc_mnt |
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Oleg Nesterov [oleg@redhat.com] wrote: | On 06/25, Sukadev Bhattiprolu wrote: | > | > Oleg Nesterov [oleg@redhat.com] wrote: | > | On 06/25, Sukadev Bhattiprolu wrote: | > | > | > | > Louis Rilling [Louis.Rilling@kerlabs.com] wrote: | > | > | - proc_pid_readdir(): | > | > | Needs similar check and protection to proc_pid_lookup(), but there is another | > | > | issue: next_tgid() can find a dying task: | > | > | > | > Hmm, I thought proc_pid_readdir() would be a problem too but convinced myself | > | > that it would not - since a process running proc_pid_readdir() would have | > | > a reference to the pid namespace, | > | | > | Where does this reference comes from ? | > | > Caller of proc_pid_readdir() would be living in the same pid namespace right ? | | Afaics, in general not. | | Suppose that we do something like | | if (!clone(CLONE_NEWPID)) { | mount("none", "/SUB_PROC", "proc", 0, NULL); | exit(); | } | | After that /SUB_PROC/ still exists, one can do "ls /SUB_PROC/".
Yes, I see it now. Thanks,
Sukadev
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