From bdf13518e79ab949c4320226a399ee4a3913ee30 Mon Sep 17 00:00:00 2001 From: Jagadeesh Krishnanjanappa Date: Mon, 30 Jul 2018 15:32:36 +0530 Subject: libxcursor: CVE-2017-16612 affects: <= 1.1.14 CVE-2017-16612: Fix heap overflows when parsing malicious files 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: Jagadeesh Krishnanjanappa Signed-off-by: Armin Kuster --- .../xorg-lib/libxcursor/CVE-2017-16612.patch | 75 ++++++++++++++++++++++ .../recipes-graphics/xorg-lib/libxcursor_1.1.14.bb | 2 + 2 files changed, 77 insertions(+) create mode 100644 meta/recipes-graphics/xorg-lib/libxcursor/CVE-2017-16612.patch diff --git a/meta/recipes-graphics/xorg-lib/libxcursor/CVE-2017-16612.patch b/meta/recipes-graphics/xorg-lib/libxcursor/CVE-2017-16612.patch new file mode 100644 index 0000000000..9a1b12e4f4 --- /dev/null +++ b/meta/recipes-graphics/xorg-lib/libxcursor/CVE-2017-16612.patch @@ -0,0 +1,75 @@ +From 4794b5dd34688158fb51a2943032569d3780c4b8 Mon Sep 17 00:00:00 2001 +From: Tobias Stoeckmann +Date: Sat, 21 Oct 2017 23:47:52 +0200 +Subject: 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. + +Upstream-Status: Backport from v1.1.15 +CVE: CVE-2017-16612 + +Signed-off-by: Jagadeesh Krishnanjanappa +--- + 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; +-- +cgit v1.1 + diff --git a/meta/recipes-graphics/xorg-lib/libxcursor_1.1.14.bb b/meta/recipes-graphics/xorg-lib/libxcursor_1.1.14.bb index 17629047b7..ccc4347820 100644 --- a/meta/recipes-graphics/xorg-lib/libxcursor_1.1.14.bb +++ b/meta/recipes-graphics/xorg-lib/libxcursor_1.1.14.bb @@ -16,6 +16,8 @@ BBCLASSEXTEND = "native nativesdk" PE = "1" +SRC_URI += "file://CVE-2017-16612.patch" + XORG_PN = "libXcursor" SRC_URI[md5sum] = "1e7c17afbbce83e2215917047c57d1b3" -- cgit 1.2.3-korg