SIGSEGV in libQt5Core.so.5 + 0x3ae793 on 39-bit address space (Cortex-A35)

[zh522130]

Box64 version: v0.4.3 8707b8d (May 25 2026), also reproduced on v0.4.1
Platform: ARM64 Cortex-A35,

Description

Running an x86_64 application that uses Qt5 (libQt5Core.so.5, Qt 5.15.2 built for x86_64/rhel6) crashes with SIGSEGV immediately after printing its startup banner.

The crash is 100% reproducible and occurs at the exact same location across box64 versions.

Crash details

[BOX64] 3529|SIGSEGV @0x7f94dda858 (???(0x7f94dda858)) (x64pc=0x3f063ae793/"/bin/../lib/libQt5Core.so.5 + 0x3ae793", rsp=0x7fabd3c6b0, stack=0x7fab53d000:0x7fabd3d000 own=(nil) fp=0x1), for accessing 0x6000fa88 (code=1/prot=87), db=0x7f94ddab80(0x7f94dda7b0:0x7f94ddac28/0x3f063ae760:0x3f063ae891//bin/../lib/libQt5Core.so.5 + 0x3ae760:clean, hash:d15feaae/d15feaae) handler=0x6917a0
RAX:0x0000000000000568 RCX:0x0000000000000001 RDX:0x0000000060000000 RBX:0x000000006000fa98
RSP:0x0000007fabd3c6b0 RBP:0x0000000000000001 RSI:0x0000000000000000 RDI:0x000000006000fa88
 R8:0x0000000000000000  R9:0x0000000000000030 R10:0x000000007324d310 R11:0x000000006000fa98
R12:0x000000007327c810 R13:0x000000007327c810 R14:0x000000007327c828 R15:0x0000007fabd3c8a8
ES:0x002b CS:0x0033 SS:0x002b DS:0x002b FS:0x0000 GS:0x0000 FSBASE=0x7fab19b010 GSBASE=(nil)
RSP-0x20:0x0000000072bab960 RSP-0x18:0x0000007fabd3c7d0 RSP-0x10:0x0000007fabd3c6b8 RSP-0x08:0x0000003f063ae770
RSP+0x00:0x0000000073278c80 RSP+0x08:0x0000003f063d94f3 RSP+0x10:0x0000000073278c80 RSP+0x18:0x0000000000000001 x64opcode=48 C7 43 F0 00 00 00 00 (opcode=f81f01bf)