1473255 - Assertion failure: cx->realm() == script->realm(), at js/src/vm/Stack.cpp:256 with sameCompartmentAs

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Christian Holler (:decoder)]

The following testcase crashes on mozilla-central revision a0e47ebc4c06 (build with --enable-posix-nspr-emulation --enable-valgrind --enable-gczeal --disable-tests --disable-profiling --enable-debug --enable-optimize, run with --fuzzing-safe):

var objs = [{}, {}];
for (var i = 0, sz = objs.length; i < sz; i++) {
  var o = objs[i];
  of (i + '  ' + o);
}
function of () {
    var g = newGlobal({
        sameCompartmentAs: this
    });
    g.f3 = function(x) {}
    g.evaluate("function f4(x) { try { return f3(x); } finally { assertCorrectRealm(); } }");
    for (var i = 0; i < 110; i++)
        g.f4(i);
}


Backtrace:

received signal SIGSEGV, Segmentation fault.
0x0000000000cb4cc0 in js::InterpreterFrame::epilogue (this=0x7ffff488b0b0, cx=0x7ffff5f17000, pc=0x7ffff5f02b38 "\231t\v") at js/src/vm/Stack.cpp:256
#0  0x0000000000cb4cc0 in js::InterpreterFrame::epilogue (this=0x7ffff488b0b0, cx=0x7ffff5f17000, pc=0x7ffff5f02b38 "\231t\v") at js/src/vm/Stack.cpp:256
#1  0x00000000005aa6c9 in Interpret (cx=0x7ffff5f17000, state=...) at js/src/vm/Interpreter.cpp:4445
#2  0x00000000005afdb6 in js::RunScript (cx=0x7ffff5f17000, state=...) at js/src/vm/Interpreter.cpp:423
#3  0x00000000005b035f in js::InternalCallOrConstruct (cx=<optimized out>, cx@entry=0x7ffff5f17000, args=..., construct=construct@entry=js::NO_CONSTRUCT) at js/src/vm/Interpreter.cpp:555
#4  0x00000000005b08bd in InternalCall (cx=0x7ffff5f17000, args=...) at js/src/vm/Interpreter.cpp:582
#5  0x00000000005b0a0a in js::CallFromStack (cx=<optimized out>, args=...) at js/src/vm/Interpreter.cpp:588
#6  0x000000000069bc53 in js::jit::DoCallFallback (cx=<optimized out>, frame=0x7fffffffc598, stub_=<optimized out>, argc=<optimized out>, vp=0x7fffffffc530, res=...) at js/src/jit/BaselineIC.cpp:2657
#7  0x000014c7ea8f828c in ?? ()
[...]
rax	0x0	0
rbx	0x7ffff488b0b0	140737295986864
rcx	0x7ffff6c282ad	140737333330605
rdx	0x0	0
rsi	0x7ffff6ef7770	140737336276848
rdi	0x7ffff6ef6540	140737336272192
rbp	0x7fffffffb7b0	140737488336816
rsp	0x7fffffffb6f0	140737488336624
r8	0x7ffff6ef7770	140737336276848
r9	0x7ffff7fe4780	140737354024832
r10	0x58	88
r11	0x7ffff6b9e7a0	140737332766624
r12	0x7ffff5f17000	140737319628800
r13	0x7fffffffbf30	140737488338736
r14	0x7fffffffb710	140737488336656
r15	0x7ffff5f02b38	140737319545656
rip	0xcb4cc0 <js::InterpreterFrame::epilogue(JSContext*, unsigned char*)+848>
=> 0xcb4cc0 <js::InterpreterFrame::epilogue(JSContext*, unsigned char*)+848>:	movl   $0x0,0x0
   0xcb4ccb <js::InterpreterFrame::epilogue(JSContext*, unsigned char*)+859>:	ud2

Comment 1

[Fuzzing Team]

JSBugMon: Bisection requested, result:
autoBisect shows this is probably related to the following changeset:

The first bad revision is:
changeset:   https://hg.mozilla.org/mozilla-central/rev/ebbddded3292
user:        Jan de Mooij
date:        Tue Jun 26 18:26:39 2018 +0200
summary:     Bug 1470904 part 1 - Switch realms before/after scripted calls if needed. r=luke

This iteration took 290.290 seconds to run.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Restore caller realm in the interpreter after calling a JITted function

The interpreter has a cx->leaveRealm call after popping an inline frame, but it also needs to do this after it called into JIT code or if we throw an exception before we finish pushing the inline frame. This patch uses MakeScopeExit for that and adds some asserts.

Comment 3

[Tom S [:evilpie]]

Comment on attachment 8989731 [details] [diff] [review]
Restore caller realm in the interpreter after calling a JITted function

Review of attachment 8989731 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/vm/Interpreter.cpp
@@ +3250,5 @@
>          funScript = fun->nonLazyScript();
>  
>          if (!activation.pushInlineFrame(args, funScript, construct))
>              goto error;
> +        leaveRealmGuard.release();

Add a comment about what leaves the frame.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/f490048b0495
Restore caller realm in the interpreter after calling a JITted function. r=evilpie

Comment 5

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/f490048b0495