[webkit-changes] [WebKit/WebKit] 6a3bc9: Cherry-pick 252432.1031 at safari-7614-branch (9f7e40...

[Commit Queue]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 6a3bc9e418ddb694dee46c4e42a9f2884296bbaa
      https://github.com/WebKit/WebKit/commit/6a3bc9e418ddb694dee46c4e42a9f2884296bbaa
  Author: David Degazio <d_degazio at apple.com>
  Date:   2023-03-28 (Tue, 28 Mar 2023)

  Changed paths:
    A JSTests/stress/cell-speculated-array-indexof.js
    M Source/JavaScriptCore/dfg/DFGFixupPhase.cpp

  Log Message:
  -----------
  Cherry-pick 252432.1031 at safari-7614-branch (9f7e401c42a8). rdar://107335776

    Fix use-after-free in DFGFixupPhase for array indexOf
    https://bugs.webkit.org/show_bug.cgi?id=250429
    rdar://103852510

    Reviewed by Jonathan Bedard and Michael Saboff.

    During DFG fixup, array indexOf nodes are folded to -1 when the search element is speculated
    to be a different type than the array element (for instance, JSCell instead of Int32). When
    this happens, a speculation check is inserted, which can cause the DFG graph's varArgChildren
    array to reallocate. This invalidates the searchElement Edge reference, which we use
    immediately after the check insertion in the fixup phase. This patch fixes this potential
    use-after-free by grabbing the searchElement's associated node before inserting any checks,
    giving us a persistent pointer to a DFG node rather than a reference into a vector.

    * JSTests/stress/cell-speculated-array-indexof.js: Added.
    * Source/JavaScriptCore/dfg/DFGFixupPhase.cpp:
    (JSC::DFG::FixupPhase::fixupArrayIndexOf):

    Canonical link: https://commits.webkit.org/252432.1031@safari-7614-branch

Canonical link: https://commits.webkit.org/262250@main