bugThe GNU Hurd - Bugs: bug #26960, firmlink opens target with client...


bug #26960: firmlink opens target with client specified flags

Submitted by:  Carl Fredrik Hammar <hammy>
Submitted on:  Sat 04 Jul 2009 04:05:50 PM UTC  
Category: Hurd ServersSeverity: 3 - Normal
Priority: 5 - NormalItem Group: None
Status: NonePrivacy: Public
Assigned to: NoneOriginator Name: 
Open/Closed: OpenReproducibility: None
Size (loc): NonePlanned Release: None
Effort: 0.00
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Sat 04 Jul 2009 04:05:50 PM UTC, original submission:

firmlink opens its target file with any client specified open
flags, except O_CREAT. This makes it is possible for a client
to read or write to the target of a firmlink using the firmlink's
authority (io_restrict_auth is not enough). It is also possible
for the client to halt firmlink's look-up midway through, using

A patch that fixes it has been attached. Also a program that
exploits the security-hole, just run it on a firmlink to a target
that it should not be permitted to read.

Carl Fredrik Hammar <hammy>
Project Member


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    Follow 2 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Sat 04 Jul 2009 04:05:51 PM UTChammyAttached File-=>Added 0001-Don-t-pass-client-flags-to-internal-firmlink-look-up.patch, #18367
      Attached File-=>Added firmlink-read.c, #18368

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