Eric Lee / smarc-fsl-linux-kernel

26 Aug, 2011

1 commit

  • be27425dc   Add a personality to report 2.6.x version numbers ... Browse Code »
    1

    I ran into a couple of programs which broke with the new Linux 3.0
    version. Some of those were binary only. I tried to use LD_PRELOAD to
    work around it, but it was quite difficult and in one case impossible
    because of a mix of 32bit and 64bit executables.

    For example, all kind of management software from HP doesnt work, unless
    we pretend to run a 2.6 kernel.

    $ uname -a
    Linux svivoipvnx001 3.0.0-08107-g97cd98f #1062 SMP Fri Aug 12 18:11:45 CEST 2011 i686 i686 i386 GNU/Linux

    $ hpacucli ctrl all show

    Error: No controllers detected.

    $ rpm -qf /usr/sbin/hpacucli
    hpacucli-8.75-12.0

    Another notable case is that Python now reports "linux3" from
    sys.platform(); which in turn can break things that were checking
    sys.platform() == "linux2":

    https://bugzilla.mozilla.org/show_bug.cgi?id=664564

    It seems pretty clear to me though it's a bug in the apps that are using
    '==' instead of .startswith(), but this allows us to unbreak broken
    programs.

    This patch adds a UNAME26 personality that makes the kernel report a
    2.6.40+x version number instead. The x is the x in 3.x.

    I know this is somewhat ugly, but I didn't find a better workaround, and
    compatibility to existing programs is important.

    Some programs also read /proc/sys/kernel/osrelease. This can be worked
    around in user space with mount --bind (and a mount namespace)

    To use:

    wget ftp://ftp.kernel.org/pub/linux/kernel/people/ak/uname26/uname26.c
    gcc -o uname26 uname26.c
    ./uname26 program

    Signed-off-by: Andi Kleen
    Signed-off-by: Linus Torvalds

    Andi Kleen
     

05 Jun, 2010

1 commit

  • 485d52768   sys_personality: change sys_personality() to accept "unsigned int" instead of u_long ... Browse Code »

    task_struct->pesonality is "unsigned int", but sys_personality() paths use
    "unsigned long pesonality". This means that every assignment or
    comparison is not right. In particular, if this argument does not fit
    into "unsigned int" __set_personality() changes the caller's personality
    and then sys_personality() returns -EINVAL.

    Turn this argument into "unsigned int" and avoid overflows. Obviously,
    this is the user-visible change, we just ignore the upper bits. But this
    can't break the sane application.

    There is another thing which can confuse the poorly written applications.
    User-space thinks that this syscall returns int, not long. This means
    that the returned value can be negative and look like the error code. But
    note that libc won't be confused and thus errno won't be set, and with
    this patch the user-space can never get -1 unless sys_personality() really
    fails. And, most importantly, the negative RET != -1 is only possible if
    that app previously called personality(RET).

    Pointed-out-by: Wenming Zhang
    Suggested-by: Linus Torvalds
    Signed-off-by: Oleg Nesterov
    Cc: "H. Peter Anvin"
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Oleg Nesterov
     

13 Jul, 2009

1 commit

  • f9fabcb58   personality: fix PER_CLEAR_ON_SETID ... Browse Code »

    We have found that the current PER_CLEAR_ON_SETID mask on Linux doesn't
    include neither ADDR_COMPAT_LAYOUT, nor MMAP_PAGE_ZERO.

    The current mask is READ_IMPLIES_EXEC|ADDR_NO_RANDOMIZE.

    We believe it is important to add MMAP_PAGE_ZERO, because by using this
    personality it is possible to have the first page mapped inside a
    process running as setuid root. This could be used in those scenarios:

    - Exploiting a NULL pointer dereference issue in a setuid root binary
    - Bypassing the mmap_min_addr restrictions of the Linux kernel: by
    running a setuid binary that would drop privileges before giving us
    control back (for instance by loading a user-supplied library), we
    could get the first page mapped in a process we control. By further
    using mremap and mprotect on this mapping, we can then completely
    bypass the mmap_min_addr restrictions.

    Less importantly, we believe ADDR_COMPAT_LAYOUT should also be added
    since on x86 32bits it will in practice disable most of the address
    space layout randomization (only the stack will remain randomized).

    Signed-off-by: Julien Tinnes
    Signed-off-by: Tavis Ormandy
    Cc: stable@kernel.org
    Acked-by: Christoph Hellwig
    Acked-by: Kees Cook
    Acked-by: Eugene Teo
    [ Shortened lines and fixed whitespace as per Christophs' suggestion ]
    Signed-off-by: Linus Torvalds

    Julien Tinnes
     

29 Apr, 2008

1 commit

13 Nov, 2006

1 commit

  • d8b295f29   [PATCH] Fix missing parens in set_personality() ... Browse Code »

    If you call set_personality() with an expression such as:

    set_personality(foo ? PERS_FOO1 : PERS_FOO2);

    then this evaluates to:

    ((current->personality == foo ? PERS_FOO1 : PERS_FOO2) ? ...

    which is obviously not the intended result. Add the missing parents
    to ensure this gets evaluated as expected:

    ((current->personality == (foo ? PERS_FOO1 : PERS_FOO2)) ? ...

    Signed-off-by: Russell King
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Russell King
     

21 Oct, 2006

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds