Mozilla released Firefox browser version 151.01 stable update yesterday, focusing on fixing crash issues that plagued users of Intel Raptor Lake (codename for Intel’s 13th and 14th generation Core processors).
After an in-depth investigation of about a year, Mozilla engineers traced the crash back to an index out-of-bounds error in the zlib-rs compression routine, but the underlying cause pointed to a hardware defect in the Intel Raptor Lake processor.
According to a blog post cited by Tech Free Press, the defects involve RPL050 and RPL060. The former prevents one CPU core from observing the latest data written by another core, while the latter returns incorrect data during split load operations across cache lines. Intel has significantly reduced the crash frequency by releasing the 0x12c microcode.
The Raptor Lake series has previously been criticized for instability. Mozilla engineer Gabriel Svelto warned that high temperatures would exacerbate timing and voltage issues in this series of CPUs.
He discovered through crash reports that Firefox crash reports from Raptor Lake systems increased significantly during the European heatwave, and he even had to turn off the automatic crash reporting bot.
In addition to crash fixes, Firefox 151.01 also addresses an issue on Windows platforms where some websites unexpectedly fail to flash device firmware using WebSerial.
