Control: tags 883792 + pending Dear maintainer,
I've prepared an NMU for libxcursor (versioned as 1:1.1.14-3.1) and uploaded it to DELAYED/2. Please feel free to tell me if I should delay it longer. Regards, Salvatore
diff -Nru libxcursor-1.1.14/debian/changelog libxcursor-1.1.14/debian/changelog --- libxcursor-1.1.14/debian/changelog 2017-08-24 08:55:44.000000000 +0200 +++ libxcursor-1.1.14/debian/changelog 2017-12-09 08:45:47.000000000 +0100 @@ -1,3 +1,11 @@ +libxcursor (1:1.1.14-3.1) unstable; urgency=medium + + * Non-maintainer upload. + * Fix heap overflows when parsing malicious files (CVE-2017-16612) + (Closes: #883792) + + -- Salvatore Bonaccorso <car...@debian.org> Sat, 09 Dec 2017 08:45:47 +0100 + libxcursor (1:1.1.14-3) unstable; urgency=medium * Team upload. diff -Nru libxcursor-1.1.14/debian/patches/Fix-heap-overflows-when-parsing-malicious-files.-CVE.patch libxcursor-1.1.14/debian/patches/Fix-heap-overflows-when-parsing-malicious-files.-CVE.patch --- libxcursor-1.1.14/debian/patches/Fix-heap-overflows-when-parsing-malicious-files.-CVE.patch 1970-01-01 01:00:00.000000000 +0100 +++ libxcursor-1.1.14/debian/patches/Fix-heap-overflows-when-parsing-malicious-files.-CVE.patch 2017-12-09 08:45:47.000000000 +0100 @@ -0,0 +1,75 @@ +From: Tobias Stoeckmann <tob...@stoeckmann.org> +Date: Sat, 21 Oct 2017 23:47:52 +0200 +Subject: Fix heap overflows when parsing malicious files. (CVE-2017-16612) +Origin: https://cgit.freedesktop.org/xorg/lib/libXcursor/commit?id=4794b5dd34688158fb51a2943032569d3780c4b8 +Bug-Debian: https://bugs.debian.org/883792 +Bug-Debian-Security: https://security-tracker.debian.org/tracker/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 <tob...@stoeckmann.org> +Reviewed-by: Matthieu Herrb <matth...@herrb.eu> +--- + src/file.c | 12 ++++++++++-- + 1 file changed, 10 insertions(+), 2 deletions(-) + +diff --git a/src/file.c b/src/file.c +index 43163c2..da16277 100644 +--- a/src/file.c ++++ b/src/file.c +@@ -29,6 +29,11 @@ XcursorImageCreate (int width, int height) + { + XcursorImage *image; + ++ if (width < 0 || height < 0) ++ return NULL; ++ if (width > XCURSOR_IMAGE_MAX_SIZE || height > XCURSOR_IMAGE_MAX_SIZE) ++ return NULL; ++ + image = malloc (sizeof (XcursorImage) + + width * height * sizeof (XcursorPixel)); + if (!image) +@@ -101,7 +106,7 @@ XcursorCommentCreate (XcursorUInt comment_type, int length) + { + XcursorComment *comment; + +- if (length > XCURSOR_COMMENT_MAX_LEN) ++ if (length < 0 || length > XCURSOR_COMMENT_MAX_LEN) + return NULL; + + comment = malloc (sizeof (XcursorComment) + length + 1); +@@ -448,7 +453,8 @@ _XcursorReadImage (XcursorFile *file, + if (!_XcursorReadUInt (file, &head.delay)) + return NULL; + /* sanity check data */ +- if (head.width >= 0x10000 || head.height > 0x10000) ++ if (head.width > XCURSOR_IMAGE_MAX_SIZE || ++ head.height > XCURSOR_IMAGE_MAX_SIZE) + return NULL; + if (head.width == 0 || head.height == 0) + return NULL; +@@ -457,6 +463,8 @@ _XcursorReadImage (XcursorFile *file, + + /* Create the image and initialize it */ + image = XcursorImageCreate (head.width, head.height); ++ if (image == NULL) ++ return NULL; + if (chunkHeader.version < image->version) + image->version = chunkHeader.version; + image->size = chunkHeader.subtype; +-- +2.15.1 + diff -Nru libxcursor-1.1.14/debian/patches/series libxcursor-1.1.14/debian/patches/series --- libxcursor-1.1.14/debian/patches/series 2017-08-24 08:55:44.000000000 +0200 +++ libxcursor-1.1.14/debian/patches/series 2017-12-09 08:45:47.000000000 +0100 @@ -1 +1,2 @@ autogen.sh-install +Fix-heap-overflows-when-parsing-malicious-files.-CVE.patch
