RESOLVED FIXED 196918
mergeOSREntryValue is wrong when the incoming value does not match up with the flush format
https://bugs.webkit.org/show_bug.cgi?id=196918
Summary mergeOSREntryValue is wrong when the incoming value does not match up with th...
Saam Barati
Reported 2019-04-15 10:51:26 PDT
Our profiling is good, so we never really run into this issue. We'd probably hit this bug way more often if we random-fuzzed the value injection types. However, once we've locked down a Variable's flushFormat, it's wrong to give it a type wider than that. E.g, we even assert that much in AI: ``` case GetLocal: { VariableAccessData* variableAccessData = node->variableAccessData(); AbstractValue value = m_state.operand(variableAccessData->local().offset()); // The value in the local should already be checked. DFG_ASSERT(m_graph, node, value.isType(typeFilterFor(variableAccessData->flushFormat()))); if (value.value()) m_state.setFoundConstants(true); setForNode(node, value); break; } ```
Attachments
patch (4.49 KB, patch)
2019-04-15 12:00 PDT, Saam Barati
no flags
Saam Barati
Comment 1 2019-04-15 12:00:11 PDT
EWS Watchlist
Comment 2 2019-04-15 12:02:15 PDT
Attachment 367438 [details] did not pass style-queue: ERROR: Source/JavaScriptCore/ChangeLog:17: Please consider whether the use of security-sensitive phrasing could help someone exploit WebKit: fuzzer, fuzzing [changelog/unwantedsecurityterms] [3] Total errors found: 1 in 4 files If any of these errors are false positives, please file a bug against check-webkit-style.
Yusuke Suzuki
Comment 3 2019-04-15 12:12:21 PDT
Comment on attachment 367438 [details] patch r=me
WebKit Commit Bot
Comment 4 2019-04-15 13:44:39 PDT
Comment on attachment 367438 [details] patch Clearing flags on attachment: 367438 Committed r244287: <https://trac.webkit.org/changeset/244287>
WebKit Commit Bot
Comment 5 2019-04-15 13:44:42 PDT
All reviewed patches have been landed. Closing bug.
Radar WebKit Bug Importer
Comment 6 2019-04-15 13:45:22 PDT
Saam Barati
Comment 7 2019-04-19 11:19:48 PDT
*** Bug 196967 has been marked as a duplicate of this bug. ***
Anthony Lai
Comment 8 2019-04-19 11:39:38 PDT
Thank you
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