1626170 - WasmOpIter.h should always call fail() when failing to read a byte

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, defect, P3)

Description

[Lars T Hansen [:lth]]

A number of readers in WasmOpIter.h will have a pattern like this:

  uint8_t tmp;
  if (!readFixedU8(&tmp)) {
    return false;
  }
  ...

This is wrong, because the decoding failure will be signaled as OOM instead of what it is, a decoding failure.

Comment 1

[Lars T Hansen [:lth]]

Attachment: Bug 1626170 - Always fail properly when failing to read input. r=bbouvier

The byte readers in WasmOpIter.h do not themselves signal error beyond
returning false. The caller must always signal a proper error (or
delegate to another caller who does the signaling), or the decoding
error will ultimately be signaled as an OOM.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/bef21a34ec25
Always fail properly when failing to read input.  r=bbouvier

Comment 3

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/bef21a34ec25