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    SubjectRe: Linux 2.1.125 doesn't dump core on SIGSEGV
    On Tue, Oct 20, 1998 at 10:55:27PM +0100, David Woodhouse wrote:

    > In the coredump case, I'm not sure - but in general it's because
    > there's a race condition. Someone can put the 'evil' symlink in
    > place between the stat() and the open().

    No, indeed you are correct - there is a race. Doh! Need more coffee.

    > Even in the coredump case there's a race, but presumably there's a
    > lock somewhere that we can use to make it seem atomic.

    How does this look (still a race, but much harder to exploit):

    if(fd = (open("core",O_CREAT | O_EXCL)) == -1)
    goto end_dump;


    /* compare stat results - don't sump if bad */



    We _really_ do need O_NOFOLLOW semantics. Anyone looked at how hard
    this would be to implement?

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