From 1ac4d12f036528e6f92019b91f260659c8d0ecc00cc86790e26cd1fe7a487d3b Mon Sep 17 00:00:00 2001 From: Stefan Dirsch Date: Tue, 28 Nov 2017 19:14:42 +0000 Subject: [PATCH] - U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch * It is possible to trigger heap overflows due to an integer overflow while parsing images and a signedness issue while parsing comments. [CVE-2017-16612] (bsc#1065386) OBS-URL: https://build.opensuse.org/package/show/X11:XOrg/libXcursor?expand=0&rev=15 --- ...lows-due-to-integer-overflow-signedn.patch | 73 +++++++++++++++++++ libXcursor.changes | 8 ++ libXcursor.spec | 5 +- 3 files changed, 85 insertions(+), 1 deletion(-) create mode 100644 U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch diff --git a/U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch b/U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch new file mode 100644 index 0000000..220b2ad --- /dev/null +++ b/U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch @@ -0,0 +1,73 @@ +From 77a4331570c660ebee77f19eb385911299948422 Mon Sep 17 00:00:00 2001 +From: Stefan Dirsch +Date: Tue, 21 Nov 2017 16:50:56 +0100 +Subject: [PATCH] Avoid heap overflows due to integer overflow + signedness + issue [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 +--- + 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; +-- +2.13.6 + diff --git a/libXcursor.changes b/libXcursor.changes index b372118..fef5414 100644 --- a/libXcursor.changes +++ b/libXcursor.changes @@ -1,3 +1,11 @@ +------------------------------------------------------------------- +Tue Nov 28 19:08:11 UTC 2017 - sndirsch@suse.com + +- U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch + * It is possible to trigger heap overflows due to an integer + overflow while parsing images and a signedness issue while + parsing comments. [CVE-2017-16612] (bsc#1065386) + ------------------------------------------------------------------- Mon Apr 28 00:57:07 UTC 2014 - sndirsch@suse.com diff --git a/libXcursor.spec b/libXcursor.spec index 97315f3..a5e850a 100644 --- a/libXcursor.spec +++ b/libXcursor.spec @@ -1,7 +1,7 @@ # # spec file for package libXcursor # -# Copyright (c) 2014 SUSE LINUX Products GmbH, Nuernberg, Germany. +# Copyright (c) 2017 SUSE LINUX GmbH, Nuernberg, Germany. # # All modifications and additions to the file contributed by third parties # remain the property of their copyright owners, unless otherwise agreed @@ -28,6 +28,8 @@ Url: http://xorg.freedesktop.org/ #Git-Clone: git://anongit.freedesktop.org/xorg/lib/libXcursor #Git-Web: http://cgit.freedesktop.org/xorg/lib/libXcursor/ Source: http://xorg.freedesktop.org/releases/individual/lib/%{name}-%{version}.tar.bz2 +Source1: baselibs.conf +Patch0: U_Avoid-heap-overflows-due-to-integer-overflow-signedn.patch BuildRoot: %{_tmppath}/%{name}-%{version}-build #git#BuildRequires: autoconf >= 2.60, automake, libtool BuildRequires: fdupes @@ -71,6 +73,7 @@ in %lname. %prep %setup -q +%patch0 -p1 %build %configure --disable-static