libXcursor: Changes to 'master'

[Matthieu Herrb]

 configure.ac |    2 +-
 src/file.c   |   12 ++++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

New commits:
commit 4828abe494df8fb4aa00dcaa22a03446ba418d01
Author: Matthieu Herrb <matthieu at herrb.eu>
Date:   Sat Nov 25 11:59:31 2017 +0100

    libXcursor 1.1.15
    
    Signed-off-by: Matthieu Herrb <matthieu at herrb.eu>

commit 4794b5dd34688158fb51a2943032569d3780c4b8
Author: Tobias Stoeckmann <tobias at stoeckmann.org>
Date:   Sat Oct 21 23:47:52 2017 +0200

    Fix heap overflows when parsing malicious files. (CVE-2017-16612)
    
    It is possible to trigger heap overflows due to an integer overflow
    while parsing images and a signedness issue while parsing comments.
    
    The integer overflow occurs because the chosen limit 0x10000 for
    dimensions is too large for 32 bit systems, because each pixel takes
    4 bytes. Properly chosen values allow an overflow which in turn will
    lead to less allocated memory than needed for subsequent reads.
    
    The signedness bug is triggered by reading the length of a comment
    as unsigned int, but casting it to int when calling the function
    XcursorCommentCreate. Turning length into a negative value allows the
    check against XCURSOR_COMMENT_MAX_LEN to pass, and the following
    addition of sizeof (XcursorComment) + 1 makes it possible to allocate
    less memory than needed for subsequent reads.
    
    Signed-off-by: Tobias Stoeckmann <tobias at stoeckmann.org>
    Reviewed-by: Matthieu Herrb <matthieu at herrb.eu>