diff --git a/0001-xlib-Fix-double-free-in-_get_image_surface.patch b/0001-xlib-Fix-double-free-in-_get_image_surface.patch new file mode 100644 index 0000000..5174a1c --- /dev/null +++ b/0001-xlib-Fix-double-free-in-_get_image_surface.patch @@ -0,0 +1,59 @@ +From d69dd6b341594c338fa6c7b327fd7f201eb37bc1 Mon Sep 17 00:00:00 2001 +From: Uli Schlachter +Date: Sat, 18 Jun 2016 15:08:52 +0200 +Subject: [PATCH] xlib: Fix double free in _get_image_surface() + +If XShmGetImage() fails, the code tries to continue with its normal, +non-shared-memory path. However, the image variable, which was previously set to +NULL, now points to an already-destroyed surface, causing a double-free when the +function cleans up after itself (actually, its an assertion failure because the +reference count of the surface is zero, but technically this is still a double +free). + +Fix this by setting image=NULL after destroying the surface that this refers to, +to make sure this surface will not be destroyed again. + +While we are here (multiple changes in a single commit are bad...), also fix the +cleanup done in bail. In practice, &image->base should be safe when image==NULL, +because this just adds some offset to the pointer (the offset here is actually +zero, so this doesn't do anything at all). However, the C standard does not +require this to be safe, so let's handle this case specially. + +Note that anything that is fixed by this change is still buggy, because the only +reason why XShmGetImage() could fail would be BadDrawable, meaning that the +target we draw to does not exist or was already destroyed. This patch will +likely just cause X11 errors elsewhere and drawing to (possible) invalid +drawables is not supported by cairo anyway. This means that if SHM fails, the +following fallback code has a high chance of failing, too. + +Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=91967 +Signed-off-by: Uli Schlachter +--- + src/cairo-xlib-surface.c | 4 +++- + 1 file changed, 3 insertions(+), 1 deletion(-) + +diff --git a/src/cairo-xlib-surface.c b/src/cairo-xlib-surface.c +index 3f407c3..555c1fe 100644 +--- a/src/cairo-xlib-surface.c ++++ b/src/cairo-xlib-surface.c +@@ -807,6 +807,7 @@ _get_image_surface (cairo_xlib_surface_t *surface, + } + + cairo_surface_destroy (&image->base); ++ image = NULL; + } + } + +@@ -1011,7 +1012,8 @@ _get_image_surface (cairo_xlib_surface_t *surface, + cairo_device_release (&display->base); + + if (unlikely (status)) { +- cairo_surface_destroy (&image->base); ++ if (image) ++ cairo_surface_destroy (&image->base); + return _cairo_surface_create_in_error (status); + } + +-- +2.7.4 + diff --git a/cairo.spec b/cairo.spec index a4dabba..208e771 100644 --- a/cairo.spec +++ b/cairo.spec @@ -5,12 +5,15 @@ Summary: A 2D graphics library Name: cairo Version: 1.14.6 -Release: 1%{?dist} +Release: 2%{?dist} URL: http://cairographics.org Source0: http://cairographics.org/releases/%{name}-%{version}.tar.xz License: LGPLv2 or MPLv1.1 Group: System Environment/Libraries +# Backported from upstream +Patch0: 0001-xlib-Fix-double-free-in-_get_image_surface.patch + Patch3: cairo-multilib.patch BuildRequires: pkgconfig @@ -86,6 +89,7 @@ This package contains tools for working with the cairo graphics library. %prep %setup -q +%patch0 -p1 %patch3 -p1 -b .multilib %build @@ -171,6 +175,9 @@ rm $RPM_BUILD_ROOT%{_libdir}/*.la %{_libdir}/cairo/ %changelog +* Mon Jul 25 2016 Kalev Lember - 1.14.6-2 +- xlib: Fix double free in _get_image_surface() (#1331021) + * Mon Apr 04 2016 Kalev Lember - 1.14.6-1 - Update to 1.14.6