=== DF-2450 FIX VALIDATION ===
=== Fixed dm.ko installed: SHA256 = f07dfdf4e480dd45d6e87fdbd270e8080dc47bc827199230c339e09db304f1c1 ===
=== Same PoC, same trigger (regular file as linear backing path) ===

[*] DF-2450 dm_pdev NULL-deref via non-block-device backing path
[*] Bug: dm_pdev_insert:168 dev_dioctl(v_rdev=NULL, DIOCGPART)
[*] Trigger: regular file as linear backing -> v_rdev NULL -> panic
[*] created regular file /tmp/df2450_backing (non-block-device vnode)
[*] create 'df2450dev': rv=0 (ok)
[*] reloading linear table with regular-file backing path...
[*] if claim is true: kernel panic in dev_dioctl (NULL v_rdev)
[!] reload rv=2 (No such file or directory) -- kernel survived
FIX_RUN_EXIT=0

=== BEFORE (unpatched #0): kernel PANIC ===
===   Stopped at dev_dioctl+0xc: movq 0xa8(%rdi),%rax   (NULL v_rdev deref) ===
=== AFTER  (fixed dm.ko):  reload rv=2 (ENOENT) -- clean rejection, no panic ===