[DragonFlyBSD - Bug #3446] (New) Boot loader hangs reading past a CD9660 directory

[sigttou]

Issue #3446 has been reported by sigttou.

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Bug #3446: Boot loader hangs reading past a CD9660 directory
http://bugs.dragonflybsd.org/issues/3446

* Author: sigttou
* Status: New
* Priority: Normal
* Category: installer
* Target version: 6.6
* Start date: 2026-10-11
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The pc32 boot loader reads a DragonFly install ISO and hangs before the
kernel starts. There is no crash and no panic; it just spins. This
happens on a normal ISO.

`cd9660_open()` in `stand/lib/cd9660.c` walks a directory record by
record. It moves the record pointer `dp` to the next record and only
then adds the record length to the byte counter `off`. Because `dp` has
already moved, `off` gets the *next* record's length, not the current
one.

On the ISO that was checked, `/boot/kernel` ends with a single                                                                                                                                 `ZLIB.KO;1` record and the next sector is the start of `aac.ko`. Its                                                                                                                           first byte `0x7f` is read as a record length of 127 and its name-length                                                                                                                        byte is 0, so the scanner never advances and the loader hangs.


---Files--------------------------------
0001-cd9660-current-record-accounting.patch (1.5 KB)


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