physmap-fault — Software

Message written by the kernel (osfmk/arm64/sleh.c) when the processor reports, in kernel mode, an access fault (unmapped page, access flag or permission) on an address in the “physical aperture” (physmap), the region that maps all of RAM. The kernel never expects a fault there: a piece of kernel code read or wrote a page that was not (or no longer) mapped, through a stale or corrupted pointer. So it is first a class of kernel software bug, not a particular driver; hardware memory corruption (a flipped bit in a pointer) is possible but rare and does not repeat identically. On two iPhone 16 logs (iOS 18.6.2) we analysed: same faulting instruction despite different addresses (KASLR), same process (mediaplaybackd), same path through apfs, copy from an unmapped physmap page (ESR 0x96000007 = level 3 translation fault): a reproducible panic on a precise code path, which points to an iOS bug rather than to the memory or the SoC.