[BUG] PhysicalDisk size wrong (saturates at 2 TiB) on 32-bit platforms for disks >2 TiB

[baracudaz]

Describe the bug

On 32-bit platforms where unsigned long is 32 bits (e.g. armv5tel with ILP32), the PhysicalDisk module reports the wrong size for any disk larger than 2 TiB. Sizes above the 32-bit sector-count limit are silently clamped to ULONG_MAX sectors instead of the real value.

To Reproduce

On a 32-bit Linux system (getconf LONG_BIT → 32) with a disk larger than 2 TiB attached (in this case a 4 TB ST4000VN000-1H41 on Debian 13/trixie, armv5tel, Marvell Kirkwood):

$ fastfetch --structure PhysicalDisk --format json
[
  {
    "type": "PhysicalDisk",
    "result": [
      {
        "name": "ATA ST4000VN000-1H41",
        "devPath": "/dev/sda",
        ...
        "size": 2199023255040,
        ...
      }
    ]
  }
]

fastfetch --pipe false renders this as 2.00 TiB.

Ground truth from the kernel is correct — the drive really is ~4 TB:

$ cat /sys/block/sda/size
7814037168
$ blockdev --getsize64 /dev/sda
4000787030016
$ lsblk -b -o NAME,SIZE,MODEL
sda 4000787030016 ST4000VN000-1H4168

Root cause

In src/detection/physicaldisk/physicaldisk_linux.c, parsePhysicalDisk() parses the sysfs size file (a 512-byte-sector count, up to 64 bits wide) with strtoul:

char blkSize[32];
ssize_t fileSize = ffReadFileDataRelative(dfd, "size", ARRAY_SIZE(blkSize) - 1, blkSize);
if (fileSize > 0) {
    blkSize[fileSize] = 0;
    size = (uint64_t) strtoul(blkSize, nullptr, 10) * 512;
}

strtoul returns unsigned long. On this platform sizeof(unsigned long) == 4, so its max value is 4294967295. The real sector count (7814037168) overflows that, and per C99 7.20.1.4/7.24.1.4 strtoul on overflow returns ULONG_MAX (and sets errno = ERANGE, which isn't checked here). So the parsed value saturates at 4294967295 sectors:

4294967295 * 512 = 2199023255040  # exactly the reported "size" above

Disks whose sector count fits in 32 bits (e.g. a 1 TB drive, 1953525168 sectors) are unaffected, which matches what's observed — the second disk in the same box reports correctly.

Suggested fix

Use a 64-bit-safe parse, e.g. strtoull/strtoumax, regardless of host long width:

size = (uint64_t) strtoull(blkSize, nullptr, 10) * 512;

System info

• fastfetch version: 2.40.4 (Debian trixie armhf/armv5tel build)
• OS: Debian GNU/Linux 13 (trixie), armv5tel
• getconf LONG_BIT: 32
• Confirmed the same strtoul call is still present on dev as of commit ba18705d (2026-07-10).