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FreeBSD Kernel Leak

Pine Digital Security announced a FreeBSD kernel leak, found when auditing a customer. The leak can be exploited to panic the server or elevate privileges. FreeBSD swiftly updated CVS, a security advisory will probably follow. Both the -RELEASE branch and -CURRENT branch are vulnerable.

81 comments

  1. Does not effect OpenBSD or NetBSD by Dan+Ost · · Score: 2, Informative

    I just wanted to point this out since whoever
    submitted the article didn't feel it was
    necessary.

    To repeat myself, according to the article, this
    problem does not effect OpenBSD or NetBSD.

    --

    *sigh* back to work...
    1. Re:Does not effect OpenBSD or NetBSD by josepha48 · · Score: 3, Informative

      Its a FreeBSD kernel bug, NetBSD and openBSD use different kernels than FreeBSD.

      --

      Only 'flamers' flame!

    2. Re:Does not effect OpenBSD or NetBSD by jasonditz · · Score: 5, Funny

      Let me just remind you all that this bug does NOT effect the OS/2 Warp 3.0 kernel.

      I repeat, the OS/2 Warp kernel is not effected!

    3. Re:Does not effect OpenBSD or NetBSD by CoolVibe · · Score: 1
      ROFL!

      *wipes coffee that was first in my mouth from screen*

      Thanks...

    4. Re:Does not effect OpenBSD or NetBSD by Anonymous Coward · · Score: 0

      Of course they do. But if you had watched exploits in *BSD over the last decade, you'll note that there is quite a deal of crossover, even in kernel bugs.

      I can't believe you moderators think this guy is informative!

    5. Re:Does not effect OpenBSD or NetBSD by Anonymous Coward · · Score: 0

      Thats funny mate :o)

    6. Re:Does not effect OpenBSD or NetBSD by Anonymous Coward · · Score: 0

      Windows XP users are also vulnerable to this bug, because so much of the code was "borrowed"...

    7. Re:Does not effect OpenBSD or NetBSD by juju2112 · · Score: 2

      Effect is not a verb -- it's a noun. The word you're looking for is affect.

    8. Re:Does not effect OpenBSD or NetBSD by josepha48 · · Score: 2
      Being a FreeBSD and NetBSD user, there is much more different code base these days. While it is true that these project share code, NetBSD does not even have the fdrop() and other f****() function that FreeBSD does in /usr/include/sys/file.h .

      If you have ever used these systems and configured kernels on these systems you would see similarities, but you would also see many more differences in kernel config parameters. The sound systems are different. FreeBSD is now using ipfirewall instead of pushing ipfilter like NetBSD and OpenBSD has a different packetfiltering mechanism.

      They are not as similar as they used to be.

      --

      Only 'flamers' flame!

    9. Re:Does not effect OpenBSD or NetBSD by LizardKing · · Score: 2

      Check your dictionary, "effect" and "affect" are both transitive verbs as well as nouns.

      Chris

    10. Re:Does not effect OpenBSD or NetBSD by Godwin+O'Hitler · · Score: 1

      Except of course only one of them means "to have an effect on", and it ain't effect.

      --
      No, your children are not the special ones. Nor are your pets.
    11. Re:Does not effect OpenBSD or NetBSD by Anonymous Coward · · Score: 0

      Well, fdrop and fhold are just named different in NetBSD (FILE_USE, FILE_UNUSE).

      Everyone needs reference counting on files ;)

      JP.

      (Yes, i should register once)

  2. Zealots... by cyb97 · · Score: 0, Troll
    That's a big blow for the BSD-zealots, I guess the linux-mob will be over this one like flies and something old ;-)...

    Remind me to stay of EFNet tonight....

    1. Re:Zealots... by Nickus · · Score: 3, Interesting

      Why would this be a big blow? It was a big problem when the latest OpenSSH bug came along. Or when Sun had a problem with NIS (I administrate multiple platforms and around 50 servers by now). It is just another security problem and in a few months we will see another one. Who cares what platforms it is. You compile, install and go on with your life.

    2. Re:Zealots... by someonehasmyname · · Score: 1

      ncftp3 ftp.kernel.org
      cd /pub/linux/kernel/v2.4
      ls *dontuse*

      linux-2.4.11-dontuse.tar.bz2
      linux-2.4.11-dontuse.tar.gz.sign
      patch-2.4.11-dontuse.gz
      linux-2.4.11-dontuse.tar.bz2.sign
      patch-2.4.11-dontuse.bz2
      patch-2.4.11-dontuse.gz.sign
      linux-2.4.11-dontuse.tar.gz
      patch-2.4.11-dontuse.bz2.sign

      So what!? Linux has had worse kernel bugs, IMHO. My FreeBSD box might be locally exploited. Anyone that rebooted their 2.4.11 Linux systems trashed any mounted filesystem.

      --
      Common sense is not so common.
    3. Re:Zealots... by hammock · · Score: 1

      Would you use something marked *dontuse* on one of your FreeBSD mirrors?

      Linux distributions only include a kernel that has been tested by the distribution builder. The people that got bit in the ass are the ones that follow the Linux Kernel Mailing List and grab new releases. The reason they follow and install bleeding edge kernels is so that they can test them out en masse for Linus and friends, and they expect to wreck thier system. That's how the linux kernel development works.

      Read the disclaimers for FreeBSD-5 previews and RC's - it's remarkably similar.

    4. Re:Zealots... by Anonymous Coward · · Score: 0

      It wasn't marked -dontuse when it was released, and 2.4.11 is not "bleeding edge".

    5. Re:Zealots... by Anonymous Coward · · Score: 0

      > administrate

      Is that similar to administer?

    6. Re:Zealots... by Anonymous Coward · · Score: 0

      Yes, it is a synonym

  3. Key Phrase by Alethes · · Score: 3, Insightful

    "FreeBSD swiftly updated CVS"

    I love open-source.

    1. Re:Key Phrase by xA40D · · Score: 3, Interesting

      "FreeBSD swiftly updated CVS"

      I love open-source.


      Indeed.

      I use FreeBSD_STABLE, I cvsup and recompile once a month. As the STABLE branch is "not vulnerable after 20021111" I'm happy to say I'd closed this particular hole 2 weeks before the FreeBSD authorities team had been informed of it's existance.

      --
      Do you mind, your karma has just run over my dogma.
  4. Re:Who cares? by Anonymous Coward · · Score: 0

    Why run Linux? Why not run Windows, where all the good progs are running even M$windoze gamez and stuff some people just want to be different and cool and make there live harder then it should be!!!!!

  5. Re:Does not affect OpenBSD or NetBSD by CoolVibe · · Score: 5, Informative
    Troll.

    Where in the story posting does it say that involves NetBSD and/or OpenBSD? It states clearly that it's a FreeBSD bug. And one that's already fixed in CVS to boot.

  6. Re:Slashdot hype linkdumping at your service by Anonymous Coward · · Score: 1, Informative

    The FreeBSD security advisory is available at ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/ FreeBSD-SA-02%3A44.filedesc.asc, including patch.

  7. Re:Slashdot hype linkdumping at your service by CoolVibe · · Score: 4, Insightful

    Read the advisory. The bug was fixed first, and then the advisory was released. Also, this security related issue isn't easy to exploit. Calling that syscall 2^31 times certainly takes a while :)

  8. Re:Who cares? by Anonymous Coward · · Score: 0

    Why run Windows? Why not go and rub yourself against people on the train, where all the good progs are running even M$windoze gamez and stuff some people just want to be different and cool and make there live harder then it should be!!!!!

  9. Re:Who cares? by filekutter · · Score: 1

    Obviously you don't use BSD, (I'll bet you bought redhat's new tripe and did a full install) or you would be extolling its virtues despite the occasional bug. Oh, btw, i doubt your intelligence since your spelling sux.......... (awaiting your feeble return-burn, you 'anonymous coward')

    --
    I call computer-illiteracy job security
  10. Re:Who cares? by Anonymous Coward · · Score: 0

    An excellent indication to lack of intelligence is in biting the post of a troll, the luring of response being the entire point of trolling. So why don't you go and blow a goat, or are you waiting for your momma?

  11. Key Phrase. by Anonymous Coward · · Score: 0

    Key phrase:

    "The leak can be exploited to panic the server or elevate privileges."

    My operating system hasn't had a remote privilege violation (let alone root exploit!) or DoS exploitability in 27 years.

    MS-DOS. No remote root exploit in 27 years.

  12. thanks, and please ignore the jerks by phippy · · Score: 4, Insightful

    i appreciate postings like this, but as usual, any good discussion about the problem is zero on slashdot.

    every time there is a mention of linux or xBSD or whatever OS having a problem, people who don't use it come out of the woodwork to say "LOOK! It sucks! It's broken! HaHaHa! We Win!".

    how old are you people ? (mentally?)
    no wonder why other tech-based sites have no respect for slashdot discussions.

    1. Re:thanks, and please ignore the jerks by satanami69 · · Score: 2

      It's mostly becuase most everyone CVSUPd and installed the fix a few weeks back.

      --
      I really hate Dan Patrick.
  13. I wish NT kernel would leak by Anonymous Coward · · Score: 1, Funny

    But then again, who'd want that source anyways?

    1. Re:I wish NT kernel would leak by Anonymous Coward · · Score: 0

      what makes you think it doesn't???

  14. Rackspace by rawg · · Score: 1, Troll

    Is this the reason that Rackspace would not let me use FreeBSD on their network 6 months ago? They said that if I use FreeBSD then I will be hacked. Then they pushed RedHad Linux on me.

    To this day, I do not know why they said FreeBSD is insecure at the Kernel.

    --
    The above is not worth reading.
    1. Re:Rackspace by Anonymous Coward · · Score: 0

      > To this day, I do not know why they said FreeBSD is insecure at the Kernel.

      Because they are morons.

    2. Re:Rackspace by eht · · Score: 1

      Considering this is a local exploit and so what if you are hacked it's your machine, they also seem to allow FreeBSD on their custom build a server option, so whatever problems they did have with it seem to be gone.

    3. Re:Rackspace by xA40D · · Score: 5, Informative

      if I use FreeBSD then I will be hacked.

      Not exactly a reprasentative poll but...

      I use FreeBSD. I work in an office with 7 other people who all use RedHat. Out of the 8 of us, over the past 2 years, I'm the only one never to have been hacked.

      The job I had before this was with an ISP which used FreeBSD for all their core systems. And in their whole history they had only ever had one FreeBSD system hacked, and that turned out to be an ex-employee who had added his public key to someobody elses authorized_keys file.

      --
      Do you mind, your karma has just run over my dogma.
    4. Re:Rackspace by sbeitzel · · Score: 3, Informative

      I have a FreeBSD machine over at Rackspace, and I found out the hard way what they meant. They only support out-of-the-box distributions. So if you cvsup the source and then rebuild your world and kernel, then if anything goes wrong with the system (say, for instance, a disk fries) they won't perform support operations as part of your built-in service fees (since you're not running on a standard configuration). Instead, you'll have to pay a premium for the support.

      --
      Oh, go on, check out my job.
    5. Re:Rackspace by R.Caley · · Score: 3, Interesting
      Is this the reason that Rackspace would not let me use FreeBSD on their network 6 months ago?

      The less cynical interpretation is that they don't have the support smarts to support FBSD.

      The cynic in me suggests they have a deal with Red Hat.

      --
      _O_
      .|<
      The named which can be named is not the true named
    6. Re:Rackspace by rawg · · Score: 1

      They do have it on their custom build. When I built my custom they told me they do not support FreeBSD anymore. This was six months ago. They said there were going to take it off their web site. I got a call from them the other day and they still do not support FreeBSD.

      --
      The above is not worth reading.
    7. Re:Rackspace by Jose · · Score: 2

      The cynic in me suggests they have a deal with Red Hat.

      what kind of deal would they have? Something like if Rackspace exclusively uses Redhat, then Rackspace gets free versions of Redhat Linux with full access to the source code? :P

      --
      The basic sleazeware produced in a drunken fury by a bunch of UCBerkeley grad students was still the core of BIND. --PV
    8. Re:Rackspace by R.Caley · · Score: 2
      The cynic in me suggests they have a deal with Red Hat.

      what kind of deal would they have?

      Cheap support? Millinary vouchers? Penguin guano scrapers?

      --
      _O_
      .|<
      The named which can be named is not the true named
    9. Re:Rackspace by rawg · · Score: 1

      Any time I post anything about Rackspace and their "use FreeBSD and get Hacked" stance, I get labled as a troll.... Why? I just don't get it....

      --
      The above is not worth reading.
  15. Re:Who cares? by filekutter · · Score: 1

    ROFLMAO!

    --
    I call computer-illiteracy job security
  16. What's the point? by Arandir · · Score: 3, Insightful

    Why was this even posted? First Slashdot posts erroneous stories. Then they start making up stories. Now they post the most trivial of stories.

    "Ho hum. Another slow news day. Let's roll some dice and post a minor random security advisory from some random project and pretend it's news."

    --
    A Government Is a Body of People, Usually Notably Ungoverned
  17. In case you didn't figure it out from the article by edhall · · Score: 5, Informative

    This is a local vulnerability; it doesn't, in and of itself, make servers vulnerable. Even if someone has a local account on a system, it takes hours of CPU time to perform an exploit.

    It looks like the bug (and the fix) were already announced (and committed to CVS) but that the possibility of using the bug in an exploit was not revealed until now (and might not even have been appreciated by the original reporter).

    -Ed
  18. Re:Slashdot hype linkdumping at your service by jasonditz · · Score: 2

    Correct me if I'm wrong but it looks like this exploit doesn't effect -STABLE to begin with.

    If you're using 5.0RC2 you've got to figure there'll be some bugs.

  19. Re:Slashdot hype linkdumping at your service by charleschuck · · Score: 1

    Correct me if I'm wrong...

    I think you are. :-)

    The security advisory says that branches RELENG_4 (up to 11 November 2002), RELENG_4_7, and RELENG_4_6 (both till 6 January 2003) contain the bug. I'd post the appropriate parts from the advisory, but the lameness filter thinks that I'm posting "junk" characters...sigh...

    -Charles

  20. Agreed... by rollthelosindice · · Score: 1
    That is the most important part of this article. Not that a patch is on the way, or that FreeBSD is thinking about fixing the problem, possibly in their next major release.

    The problem is already fixed, and people just need to update themselves now.

  21. Re:Slashdot hype linkdumping at your service by Stonehead · · Score: 1

    Thanks! That link was what I was waiting for, what Coolvibe refers to and what Slashdot still should have linked to. I deserved a slap for not having checked www.freebsd.org myself first.

  22. Re:Slashdot hype linkdumping at your service by bsdbigot · · Score: 1

    Incorrect... this affects 4.3 and later. It does effect -STABLE up until the point where the patch was installed. -STABLE is a line off of a release where tested new features, bug fixes, and security patches are applied. Thus, you could install a -RELEASE and then track -STABLE, but you would generally only do this if you were engaged in actively developing (on) FreeBSD. If you were using a -STABLE before this came to light, you are still vulnerable unless you've updated since.

    5.0 may or may not be affected - I would assume the former, but I may be wrong.

    For more information on -CURRENT and -STABLE...

    --
    main(){char I,l,O[]={'-',1-1,0,(1<<5)-1,0+'-',-10-1,-10,11-0,- 1,-100};for(I=l=0;l<10+0;put
  23. Re:First post by cant_get_a_good_nick · · Score: 2

    A first post that actually makes some amount of sense? True "First" indeed.

  24. Re:In case you didn't figure it out from the artic by quillsta · · Score: 1

    Ya know Ed you da man! I was pretty sure it was local and not the average script kiddie's folly; however, wanting to see how long it took for someone to confirm my drunken belief and now I am way down here in the replies :).

    Begin_Rant

    Too much wah wah FreeBSD, Not OPEN or NET blather to give people, who may need direction and are unfamiliar, the proper support and information they deserve --hats off to you for pointing the truth out.

    Afterall, it's the community spirit being fostered by the BSD and Linux and Open Source Movements that needs to be agressively passed along to the newly initiated cause we all know....

    The DOCUMENTATION SUCKS, so the community needs to make up for it, or we'll all have Borg implants, M$ alarm clocks that don't wake us up for work, microwave ovens that can't cook a decent buttered popcorn, and Oracle poptarts that are still cold out of the toaster.

    Having a choice makes up for small road block which are already fixed and gone.

    Surely some people have a few production servers will probably need to be patched against this due to the service that they provide, but the odds that they'll get caught with their asses hanging out are slim to none and even the slightest of process monitoring would smell that in a hearbeat.

    Any OS needs help out of the box and takes a clear and goal oriented approach to make it secure and tuned in any sense to the mold in which you want it to fit.

    Too bad people would rather speak than what consider what people may want to hear....It obscures the point. I think the post meant well, but was the starting point of a degraded dialogue (minus my $0.02 of course :) )

    End_Rant

    -Quillsta

  25. Re:FREEBSD IS DYING by quillsta · · Score: 1

    ROFL. It's Far from dying. Keep trolling, maybe get yourself a little pink imac to go with your leotard.

  26. FreeBSD is dyeing by TardisX · · Score: 1
    in other news today, Core announced today that they'd be changing the FreeBSD kernel from it's current red colour, to mauve, since it has more RAM.

    --

    Command attempted to use minibuffer while in minibuffer
    1. Re:FreeBSD is dyeing by Anonymous Coward · · Score: 0

      Ha ha Dilbert,

      Anyway a problem of stupid error:

      How irritating tryed to put down the
      offending code here but slashdot
      said it was lame because I had to many junk characters news for nerds?? Anyway its in /sys/kern/kern_descrip.c

  27. -1, Too Subtle by Godwin+O'Hitler · · Score: 1

    You did a nice job of writing something that went over most people's heads there :)

    --
    No, your children are not the special ones. Nor are your pets.
  28. Of course the OS/2 wasn't effected! by Anonymous Coward · · Score: 0

    The word you were looking for was affected, not effected.

    Stupid geeks and their third grade english skills.

    1. Re:Of course the OS/2 wasn't effected! by Anonymous Coward · · Score: 0

      First of all, if he were to speak that sentence, you most likely would not be able to determine whether he said "affected" or "effected." Also, the fact that you were able to correct him indicates that you knew the meaning of his sentence, so was it really necessary to correct him?

      Second, "stupids geek and their third grade English skills." "English" is a proper noun and should be capitalized appropriately.

    2. Re:Of course the OS/2 wasn't effected! by jasonditz · · Score: 2

      The most enjoyable part of the whole topic is the fact that you corrected me, and you couldn't be more wrong if you tried.

      Affected

      1 : INCLINED, DISPOSED

      2 a : given to affectation b : assumed artificially or falsely : PRETENDED

      So tell me Captain English, which of those is the correct definition? According to m-w.com:

      usage The confusion of the verbs affect and effect is not only quite common but has a long history. Effect was used in place of affect as early as 1494. If you think you want to use the verb effect but are not certain, check the definitions in this dictionary. The noun affect is sometimes mistakenly used for effect. Except when your topic is psychology, you will seldom need the noun affect.

      So unless you thought I meant that the exploit had great fondness for OS/2, I stand uncorrected.

    3. Re:Of course the OS/2 wasn't effected! by almeida · · Score: 2

      You are wrong. The definition you cite for affected is not relevent as it is an adjective. The word in question is effect, which you used as a verb in your sentence: "Let me just remind you all that this bug does NOT effect the OS/2 Warp 3.0 kernel."

      From dictionary.com, definition 1 of affect: "To have an influence on or effect a change in."

      Also from dictionary.com, effect as a verb means "To produce, as a cause or agent; to cause to be." or "To bring to pass; to execute; to enforce; to achieve; to accomplish."

      The leak isn't producing, executing, enforcing, achieving, or accomplishing FreeBSD. It is, however, having an influence or effect on FreeBSD.

      So, your grammar argument is completely wrong. Technically, however, your original sentence isn't completely wrong because the bug does not effect OS/2. In this context, you really meant that is does not affect OS/2.

    4. Re:Of course the OS/2 wasn't effected! by Groganz · · Score: 1

      Now that we have grammatically analysed the joke the funniness has been sucked from it.

    5. Re:Of course the OS/2 wasn't effected! by Anonymous Coward · · Score: 0

      Depends on the dialect of English.
      Do not try to apply Latin grammar
      to the mother tongue.

    6. Re:Of course the OS/2 wasn't effected! by Anonymous Coward · · Score: 0

      You used the wrong definition from m-w.com. You needed to use the transitive version (definition 3).

      Main Entry: affect

      Function: transitive verb

      Etymology: Middle English, from affectus, past participle of afficere

      Date: 15th century
      : to produce an effect upon: as a : to produce a material influence upon or alteration in <paralysis affect ed his limbs> b : to act upon (as a person or a person's mind or feelings) so as to effect a response: INFLUENCE


      You were wrong, but it wasn't important. Since you decided to justify your error with the wrong definition, however, I thought I'd point that out.

      -Dan

  29. Re:In case you didn't figure it out from the artic by nutznboltz · · Score: 2

    Are you completely sure that no network daemon can be coerced into calling fpathconf() repetitively?

  30. Re:In case you didn't figure it out from the artic by edhall · · Score: 3, Informative

    The problem isn't calling just calling fpathconf() repetitively. The problem is calling fpathconf() repetitively on a socket or other non-file (which would be a bug in itself). And by "repetitively" I mean at least 2,147,483,648 times on the same file descriptor for a system panic exploit, and exactly 4,294,967,295 times on the same file descriptor (followed by a close()) for the priviledge escalation exploit.

    No network daemon that is part of the FreeBSD base system can be coerced into performing the necessary actions. Grep the source tree yourself (you'll only get a handful of hits) and examine the resulting files if you don't believe me. It's impossible to rule out everything in the ports collection (and the FreeBSD folks are careful not to make any claims regarding them) but it's hard to imagine creating an exploit of greater than theoretical importance using any network server.

    -Ed
  31. Maybe the most interesting bit is... by cesarcardoso · · Score: 1

    > Although the missing fdrop() call in fpathconf(2) was noticed
    > before by Nakamura Takayuki its impact
    > was severely underestimated.

    As someone noticed before, it looks like a known bug, but until now nobody has really done the check, "hey, what this bug does?".

    Maybe now the FreeBSD Core team knows why they fixed the bug :)

    --
    Cesar Cardoso can be found at cesar at zyakannazio dot eti dot br (or at least I believe so)
  32. M$ Windows Not affected either by Anonymous Coward · · Score: 0

    I mean if we are going to be retarted and point out the obvious..

    Neither is Mac OS's affected either

  33. Re:Slashdot hype linkdumping at your service by Anonymous Coward · · Score: 0

    The security advisory has already been posted before it gets to Slashdot.

  34. Re:FREEBSD IS DYING by Anonymous Coward · · Score: 0

    if its not dying why are you responding to his post ? bwahahaha! admit it. freebsd is dying.

  35. Re:BSD IS DYING! by Anonymous Coward · · Score: 0

    Dead or not, its still my favorite OS.

    Joost Pol

    PS: previous post is flamebait ;)

  36. why would you be reading and posting here? by ToastedBagel · · Score: 1

    > how old are you people ? (mentally?)
    > no wonder why other tech-based sites have no respect for slashdot discussions.

    I'd say that that's what's so great about slashdot, its egalitarian nature. Sure, you see many stupid posts (you might say that this post is stupid as well), but the fact that anyone can contribute to slashdot makes this place magical and dynamic; stupid posts are just a minor consequence. And let me ask you; if you think that slashdot is just a morons and idiots get-together, why would you be reading and posting here?