- Revision
- 186840
- Author
- [email protected]
- Date
- 2015-07-15 09:02:39 -0700 (Wed, 15 Jul 2015)
Log Message
Negative scroll snap repeat values cause web process to hang indefinitely
https://bugs.webkit.org/show_bug.cgi?id=146953
Source/WebCore:
<rdar://problem/21823681>
Patch by Wenson Hsieh <[email protected]> on 2015-07-15
Reviewed by Simon Fraser.
Fixed dangerous behavior caused by setting -scroll-snap-points-x or -y to negative or very small
positive values. In the case of negative or 0 repeats, the web process would hang indefinitely. In
the case of very small positive values, a massive amount of memory could potentially be allocated
just to store snap offsets.
Tests: css3/scroll-snap/scroll-snap-negative-repeat.html
css3/scroll-snap/scroll-snap-subpixel-repeat.html
* css/CSSParser.cpp:
(WebCore::CSSParser::parseNonElementSnapPoints): Changed to consider negative snap repeat values as invalid CSS.
* page/scrolling/AxisScrollSnapOffsets.cpp:
(WebCore::updateFromStyle): Changed to threshold non-negative snap repeat values to 1px.
LayoutTests:
Patch by Wenson Hsieh <[email protected]> on 2015-07-15
Reviewed by Simon Fraser.
The first test case checks that setting -scroll-snap-points-x or -y to a negative value
will not cause the web process to hang. The second test case (in a similar vein) checks
that tiny subpixel snap repeats generate a reasonable number of snap offsets.
* css3/scroll-snap/scroll-snap-negative-repeat-expected.txt: Added.
* css3/scroll-snap/scroll-snap-negative-repeat.html: Added.
* css3/scroll-snap/scroll-snap-subpixel-repeat-expected.txt: Added.
* css3/scroll-snap/scroll-snap-subpixel-repeat.html: Added.
Modified Paths
Added Paths
Diff
Modified: trunk/LayoutTests/ChangeLog (186839 => 186840)
--- trunk/LayoutTests/ChangeLog 2015-07-15 16:01:32 UTC (rev 186839)
+++ trunk/LayoutTests/ChangeLog 2015-07-15 16:02:39 UTC (rev 186840)
@@ -1,3 +1,19 @@
+2015-07-15 Wenson Hsieh <[email protected]>
+
+ Negative scroll snap repeat values cause web process to hang indefinitely
+ https://bugs.webkit.org/show_bug.cgi?id=146953
+
+ Reviewed by Simon Fraser.
+
+ The first test case checks that setting -scroll-snap-points-x or -y to a negative value
+ will not cause the web process to hang. The second test case (in a similar vein) checks
+ that tiny subpixel snap repeats generate a reasonable number of snap offsets.
+
+ * css3/scroll-snap/scroll-snap-negative-repeat-expected.txt: Added.
+ * css3/scroll-snap/scroll-snap-negative-repeat.html: Added.
+ * css3/scroll-snap/scroll-snap-subpixel-repeat-expected.txt: Added.
+ * css3/scroll-snap/scroll-snap-subpixel-repeat.html: Added.
+
2015-07-15 David Kilzer <[email protected]>
http/tests/misc/large-js-program.php crashes slowly in Debug builds on Windows
Added: trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat-expected.txt (0 => 186840)
--- trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat-expected.txt (rev 0)
+++ trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat-expected.txt 2015-07-15 16:02:39 UTC (rev 186840)
@@ -0,0 +1,9 @@
+Tests that negative repeat() values don't hang on snap point computation.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+
Added: trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat.html (0 => 186840)
--- trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat.html (rev 0)
+++ trunk/LayoutTests/css3/scroll-snap/scroll-snap-negative-repeat.html 2015-07-15 16:02:39 UTC (rev 186840)
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+ <head>
+ <style>
+ body {
+ -webkit-scroll-snap-type: mandatory;
+ -webkit-scroll-snap-points-y: repeat(-400px);
+ height: 5000px;
+ }
+ </style>
+ <script src=""
+ </head>
+ <body>
+ <div id="console"></div>
+ <script>
+ description("Tests that negative repeat() values don't hang on snap point computation.");
+ </script>
+ <script src=""
+ </body>
+</html>
+
Added: trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat-expected.txt (0 => 186840)
--- trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat-expected.txt (rev 0)
+++ trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat-expected.txt 2015-07-15 16:02:39 UTC (rev 186840)
@@ -0,0 +1,13 @@
+Tests that small positive repeat() values generates a reasonable number of snap offsets.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+PASS successfullyParsed is true
+
+TEST COMPLETE
+Number of snap offsets: 99
+PASS successfullyParsed is true
+
+TEST COMPLETE
+
Added: trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat.html (0 => 186840)
--- trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat.html (rev 0)
+++ trunk/LayoutTests/css3/scroll-snap/scroll-snap-subpixel-repeat.html 2015-07-15 16:02:39 UTC (rev 186840)
@@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<html>
+ <head>
+ <style>
+ #gallery {
+ height: 100px;
+ width: 100px;
+ overflow-x: hidden;
+ overflow-y: auto;
+ -webkit-scroll-snap-type: mandatory;
+ -webkit-scroll-snap-points-y: repeat(0.0001px);
+ margin: 0;
+ padding: 0;
+ }
+
+ .colorBox {
+ width: 100px;
+ height: 100px;
+ }
+
+ #item0 { background-color: red; }
+ #item1 { background-color: green; }
+ </style>
+ <script src=""
+ <script>
+ function runTest()
+ {
+ var gallery = document.getElementById("gallery");
+
+ if (window.testRunner) {
+ window.jsTestIsAsync = true;
+ testRunner.dumpAsText();
+ testRunner.waitUntilDone();
+ setTimeout(dumpSnapOffsets, 0);
+ }
+
+ function snapOffsetsFromString(offsetsAsString)
+ {
+ var startIndex = offsetsAsString.search(/\{/);
+ var endIndex = offsetsAsString.search(/\}/);
+ if (startIndex == -1 || endIndex == -1 || endIndex <= startIndex)
+ return []
+
+ return offsetsAsString
+ .substring(startIndex + 1, endIndex - startIndex - 1)
+ .trim()
+ .split(",")
+ .map(function(s) { return parseFloat(s.trim()) });
+ }
+
+ function dumpSnapOffsets()
+ {
+ var offsets = snapOffsetsFromString(window.internals.scrollSnapOffsets(gallery));
+ debug("Number of snap offsets: " + offsets.length);
+ finishJSTest();
+ }
+ }
+ </script>
+ </head>
+ <body _onload_="runTest()">
+ <div id="gallery">
+ <div id="item0" class="colorBox"></div>
+ <div id="item1" class="colorBox"></div>
+ </div>
+ <div id="console"></div>
+ <script>
+ description("Tests that small positive repeat() values generates a reasonable number of snap offsets.");
+ </script>
+ <script src=""
+ </body>
+</html>
Modified: trunk/Source/WebCore/ChangeLog (186839 => 186840)
--- trunk/Source/WebCore/ChangeLog 2015-07-15 16:01:32 UTC (rev 186839)
+++ trunk/Source/WebCore/ChangeLog 2015-07-15 16:02:39 UTC (rev 186840)
@@ -1,3 +1,24 @@
+2015-07-15 Wenson Hsieh <[email protected]>
+
+ Negative scroll snap repeat values cause web process to hang indefinitely
+ https://bugs.webkit.org/show_bug.cgi?id=146953
+ <rdar://problem/21823681>
+
+ Reviewed by Simon Fraser.
+
+ Fixed dangerous behavior caused by setting -scroll-snap-points-x or -y to negative or very small
+ positive values. In the case of negative or 0 repeats, the web process would hang indefinitely. In
+ the case of very small positive values, a massive amount of memory could potentially be allocated
+ just to store snap offsets.
+
+ Tests: css3/scroll-snap/scroll-snap-negative-repeat.html
+ css3/scroll-snap/scroll-snap-subpixel-repeat.html
+
+ * css/CSSParser.cpp:
+ (WebCore::CSSParser::parseNonElementSnapPoints): Changed to consider negative snap repeat values as invalid CSS.
+ * page/scrolling/AxisScrollSnapOffsets.cpp:
+ (WebCore::updateFromStyle): Changed to threshold non-negative snap repeat values to 1px.
+
2015-07-14 Dean Jackson <[email protected]>
Placeholder colors should be system grays
Modified: trunk/Source/WebCore/css/CSSParser.cpp (186839 => 186840)
--- trunk/Source/WebCore/css/CSSParser.cpp 2015-07-15 16:01:32 UTC (rev 186839)
+++ trunk/Source/WebCore/css/CSSParser.cpp 2015-07-15 16:02:39 UTC (rev 186840)
@@ -3397,7 +3397,7 @@
&& value->function->args->size() == 1
&& equalIgnoringCase(value->function->name, "repeat(")) {
ValueWithCalculation argumentWithCalculation(*value->function->args.get()->current());
- if (validateUnit(argumentWithCalculation, FLength | FPercent)) {
+ if (validateUnit(argumentWithCalculation, FLength | FPercent | FNonNeg)) {
values->append(cssValuePool().createValue(LengthRepeat::create(createPrimitiveNumericValue(argumentWithCalculation))));
m_valueList->next();
if (m_valueList->current())
Modified: trunk/Source/WebCore/page/scrolling/AxisScrollSnapOffsets.cpp (186839 => 186840)
--- trunk/Source/WebCore/page/scrolling/AxisScrollSnapOffsets.cpp 2015-07-15 16:01:32 UTC (rev 186839)
+++ trunk/Source/WebCore/page/scrolling/AxisScrollSnapOffsets.cpp 2015-07-15 16:02:39 UTC (rev 186840)
@@ -87,7 +87,9 @@
auto* points = (axis == ScrollEventAxis::Horizontal) ? style.scrollSnapPointsX() : style.scrollSnapPointsY();
bool hasRepeat = points ? points->hasRepeat : false;
- LayoutUnit repeatOffset = points ? valueForLength(points->repeatOffset, viewSize) : LayoutUnit();
+ LayoutUnit repeatOffset = points ? valueForLength(points->repeatOffset, viewSize) : LayoutUnit::fromPixel(1);
+ repeatOffset = std::max<LayoutUnit>(repeatOffset, LayoutUnit::fromPixel(1));
+
LayoutUnit destinationOffset = destinationOffsetForViewSize(axis, style.scrollSnapDestination(), viewSize);
LayoutUnit curSnapPositionShift = 0;
LayoutUnit maxScrollOffset = scrollSize - viewSize;
