Messages in this thread | | | Date | Tue, 14 Sep 2004 12:05:09 -0700 | From | Chris Wright <> | Subject | Re: [1/1][PATCH] nproc v2: netlink access to /proc information |
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* Roger Luethi (rl@hellgate.ch) wrote: > On Tue, 14 Sep 2004 11:37:36 -0700, Chris Wright wrote: > > Canonical example is access(2) followed by open(2), not really relevant > > in this case. However, exec setuid root app...when do you check, and > > when to you fill in data to send back to user? For /proc, this type of > > check happens often (see things like may_ptrace_attach and > > task_dumpable in fs/proc/base.c). > > For nproc, the procedure looks like this: A tool send(2)s a request, > credentials are attached to skb. Based on said credentials, the kernel > is free to provide (netlink_unicast to originating socket) or withhold > information. In this regard, nproc works like other netlink interfaces.
Understood. Question is, if the request is for data that's associated with a task that is in the middle of an execve(setuid_root_app), does the credential-check/skb-fill for response happen atomically w.r.t. said execve? IOW, is it possible to pass credential check, then fill data that's become sensitive since the check happened?
thanks, -chris -- Linux Security Modules http://lsm.immunix.org http://lsm.bkbits.net - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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